Extension Tools MCP Server
@mcp-b/extension-tools
npm
v4.0.0
Source verified
Published by webmcp-org — publish provenance cryptographically ties this package to that repository. That is proof of origin, not an official vendor package.
62+ Chrome Extension API tools for Model Context Protocol (MCP) - Let AI agents control tabs, bookmarks, history, storage, and more
The grade answers one question — how safe is this server for you to adopt — so it is computed in two auditable stages. Nothing below is an opinion or an LLM's guess; every line is a real term the deterministic engine applied, and the same input always yields the same number.
1. Threat score — 100 − 0 = 100. What the published surface and source actually contain:
The deterministic scan raised no scored threat in the surface it inspected — the threat score stayed at 100. Capability observations and advisory notes are recorded but never lower it.
2. Client adoption risk — 100 − 10 = 90. Three small, subtract-only factors that reflect your risk in adopting it — a clean scan proves less on a powerful, unverified or barely-inspectable package, so the grade says so plainly:
| Points | Adoption-risk factor |
|---|---|
| −10 | capability blast radius (critical) — client exposure if the model is manipulated |
Capability observations and info notes are shown under Findings but never scored.
Open any row's finding below for the file, line and evidence behind a deduction.
Findings 17
critical Completed toxic-flow trifecta across toolsMTC-FLOW-002
This server (without client built-ins) exposes a complete data-exfiltration chain: extension_tool_accept_danger → extension_tool_get_tokens → extension_tool_clear_font. Untrusted input is ingested, private data is read, and it can be sent to an external sink via the agent composing the tools (→). Static analysis proves the primitive exists, not that a specific run will occur.
Fix: Remove one leg of the trifecta: isolate untrusted-input tools from secret-reading tools and from egress tools, or require human approval between them.
Location: flow extension_tool_accept_danger → extension_tool_get_tokens → extension_tool_clear_font
high Tool "extension_tool_eval_inspected_window" exposes command/code executionMTC-CAP-001
Tool "extension_tool_eval_inspected_window" appears to run shell commands or evaluate code (keyword "eval" in tool name). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.
Fix: Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.
Location: tool extension_tool_eval_inspected_window
high Tool "extension_tool_get_font" exposes command/code executionMTC-CAP-001
Tool "extension_tool_get_font" appears to run shell commands or evaluate code (parameter "script"). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.
Fix: Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.
Location: tool extension_tool_get_font
high Tool "extension_tool_set_font" exposes command/code executionMTC-CAP-001
Tool "extension_tool_set_font" appears to run shell commands or evaluate code (parameter "script"). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.
Fix: Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.
Location: tool extension_tool_set_font
high Tool "extension_tool_clear_font" exposes command/code executionMTC-CAP-001
Tool "extension_tool_clear_font" appears to run shell commands or evaluate code (parameter "script"). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.
Fix: Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.
Location: tool extension_tool_clear_font
medium Unconstrained URL/host parameter "url" on "extension_tool_download_file"MTC-CAP-007
Tool "extension_tool_download_file" takes a URL/host parameter "url" with no allowlist/pattern. An outbound-request tool with an unbounded destination enables SSRF and cloud-metadata access (e.g. 169.254.169.254).
Fix: Allowlist destinations or constrain the parameter; block private/link-local addresses server-side.
Location: tool extension_tool_download_file · inputSchema.properties.url
medium Tool "extension_tool_remove_file_systems" can modify the filesystemMTC-CAP-002
Tool "extension_tool_remove_file_systems" can write, overwrite or delete files (keyword "remove_file" in tool name). Verify it is scoped to a safe directory.
Fix: Constrain file operations to an explicit, non-sensitive root; reject path traversal.
Location: tool extension_tool_remove_file_systems
medium Tool "extension_tool_remove_file" can modify the filesystemMTC-CAP-002
Tool "extension_tool_remove_file" can write, overwrite or delete files (keyword "remove_file" in tool name). Verify it is scoped to a safe directory.
Fix: Constrain file operations to an explicit, non-sensitive root; reject path traversal.
Location: tool extension_tool_remove_file
medium Unconstrained command parameter "script" on "extension_tool_get_font"MTC-CAP-006
Tool "extension_tool_get_font" takes a command-shaped parameter "script" with no enum/pattern constraint. Free-form, model- or attacker-controlled arguments reaching a shell is the command-injection precondition.
Fix: Constrain the parameter (enum/pattern), or build the command from a fixed template with escaped args.
Location: tool extension_tool_get_font · inputSchema.properties.script
medium Unconstrained command parameter "script" on "extension_tool_set_font"MTC-CAP-006
Tool "extension_tool_set_font" takes a command-shaped parameter "script" with no enum/pattern constraint. Free-form, model- or attacker-controlled arguments reaching a shell is the command-injection precondition.
Fix: Constrain the parameter (enum/pattern), or build the command from a fixed template with escaped args.
Location: tool extension_tool_set_font · inputSchema.properties.script
medium Unconstrained command parameter "script" on "extension_tool_clear_font"MTC-CAP-006
Tool "extension_tool_clear_font" takes a command-shaped parameter "script" with no enum/pattern constraint. Free-form, model- or attacker-controlled arguments reaching a shell is the command-injection precondition.
Fix: Constrain the parameter (enum/pattern), or build the command from a fixed template with escaped args.
Location: tool extension_tool_clear_font · inputSchema.properties.script
low Mutating tool "extension_tool_remove_file_systems" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_remove_file_systems" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_remove_file_systems
low Mutating tool "extension_tool_eval_inspected_window" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_eval_inspected_window" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_eval_inspected_window
low Mutating tool "extension_tool_remove_file" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_remove_file" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_remove_file
low Mutating tool "extension_tool_get_font" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_get_font" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_get_font
low Mutating tool "extension_tool_set_font" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_set_font" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_set_font
low Mutating tool "extension_tool_clear_font" declares no destructiveHintMTC-CAP-005
Tool "extension_tool_clear_font" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool extension_tool_clear_font
Tools 200
Each tool and what it can reach — statically extracted from the published source.
extension_tool_remove_fileingests untrusted inputwrites filesextension_tool_accept_dangeringests untrusted inputextension_tool_cancel_downloadingests untrusted inputextension_tool_clear_fontruns code / shellextension_tool_download_fileingests untrusted inputextension_tool_eval_inspected_windowruns code / shellextension_tool_get_file_iconingests untrusted inputextension_tool_get_fontruns code / shellextension_tool_get_tokensreads sensitive dataextension_tool_open_downloadingests untrusted input
Show 190 more tools ↓
extension_tool_pause_downloadingests untrusted inputextension_tool_remove_downloadsingests untrusted inputextension_tool_remove_file_systemswrites filesextension_tool_resume_downloadingests untrusted inputextension_tool_set_fontruns code / shellextension_tool_set_ui_optionsingests untrusted inputextension_tool_show_downloadingests untrusted inputextension_tool_add_declarative_rulesno sensitive capabilityextension_tool_add_execute_listenerno sensitive capabilityextension_tool_attach_debuggerno sensitive capabilityextension_tool_bookmark_operationsno sensitive capabilityextension_tool_bookmark_parameters_descriptionno sensitive capabilityextension_tool_cancel_choose_desktop_mediano sensitive capabilityextension_tool_cancel_scanno sensitive capabilityextension_tool_challenge_machine_keyno sensitive capabilityextension_tool_challenge_user_keyno sensitive capabilityextension_tool_choose_desktop_mediano sensitive capabilityextension_tool_clear_alarmno sensitive capabilityextension_tool_clear_all_alarmsno sensitive capabilityextension_tool_clear_all_cached_auth_tokensno sensitive capabilityextension_tool_clear_auto_verify_settingno sensitive capabilityextension_tool_clear_automatic_downloads_settingno sensitive capabilityextension_tool_clear_camera_settingno sensitive capabilityextension_tool_clear_clipboard_settingno sensitive capabilityextension_tool_clear_compositionno sensitive capabilityextension_tool_clear_cookies_settingno sensitive capabilityextension_tool_clear_default_fixed_font_sizeno sensitive capabilityextension_tool_clear_default_font_sizeno sensitive capabilityextension_tool_clear_images_settingno sensitive capabilityextension_tool_clear_javascript_settingno sensitive capabilityextension_tool_clear_location_settingno sensitive capabilityextension_tool_clear_microphone_settingno sensitive capabilityextension_tool_clear_minimum_font_sizeno sensitive capabilityextension_tool_clear_notifications_settingno sensitive capabilityextension_tool_clear_popups_settingno sensitive capabilityextension_tool_close_scannerno sensitive capabilityextension_tool_commit_textno sensitive capabilityextension_tool_create_alarmno sensitive capabilityextension_tool_create_context_menuno sensitive capabilityextension_tool_create_panelno sensitive capabilityextension_tool_create_sidebar_paneno sensitive capabilityextension_tool_detach_debuggerno sensitive capabilityextension_tool_detect_languageno sensitive capabilityextension_tool_document_scanno sensitive capabilityextension_tool_erase_downloadsno sensitive capabilityextension_tool_gcm_registerno sensitive capabilityextension_tool_gcm_sendno sensitive capabilityextension_tool_gcm_unregisterno sensitive capabilityextension_tool_get_accept_languagesno sensitive capabilityextension_tool_get_accountsno sensitive capabilityextension_tool_get_alarmno sensitive capabilityextension_tool_get_all_alarmsno sensitive capabilityextension_tool_get_all_commandsno sensitive capabilityextension_tool_get_all_cookie_storesno sensitive capabilityextension_tool_get_all_cookiesno sensitive capabilityextension_tool_get_all_file_systemsno sensitive capabilityextension_tool_get_audio_devicesno sensitive capabilityextension_tool_get_audio_muteno sensitive capabilityextension_tool_get_auth_tokenno sensitive capabilityextension_tool_get_auto_lock_delayno sensitive capabilityextension_tool_get_auto_verify_settingno sensitive capabilityextension_tool_get_automatic_downloads_settingno sensitive capabilityextension_tool_get_available_static_rule_countno sensitive capabilityextension_tool_get_background_pageno sensitive capabilityextension_tool_get_browsing_data_settingsno sensitive capabilityextension_tool_get_camera_settingno sensitive capabilityextension_tool_get_certificatesno sensitive capabilityextension_tool_get_clipboard_settingno sensitive capabilityextension_tool_get_cookieno sensitive capabilityextension_tool_get_cookies_settingno sensitive capabilityextension_tool_get_debug_targetsno sensitive capabilityextension_tool_get_declarative_rulesno sensitive capabilityextension_tool_get_default_fixed_font_sizeno sensitive capabilityextension_tool_get_default_font_sizeno sensitive capabilityextension_tool_get_device_annotated_locationno sensitive capabilityextension_tool_get_device_asset_idno sensitive capabilityextension_tool_get_device_hostnameno sensitive capabilityextension_tool_get_device_serial_numberno sensitive capabilityextension_tool_get_directory_device_idno sensitive capabilityextension_tool_get_dynamic_rulesno sensitive capabilityextension_tool_get_enabled_rulesetsno sensitive capabilityextension_tool_get_execute_event_detailsno sensitive capabilityextension_tool_get_file_systemno sensitive capabilityextension_tool_get_font_listno sensitive capabilityextension_tool_get_harno sensitive capabilityextension_tool_get_hardware_platform_infono sensitive capabilityextension_tool_get_images_settingno sensitive capabilityextension_tool_get_inspected_window_resourcesno sensitive capabilityextension_tool_get_javascript_settingno sensitive capabilityextension_tool_get_location_settingno sensitive capabilityextension_tool_get_matched_rulesno sensitive capabilityextension_tool_get_messageno sensitive capabilityextension_tool_get_microphone_settingno sensitive capabilityextension_tool_get_minimum_font_sizeno sensitive capabilityextension_tool_get_network_detailsno sensitive capabilityextension_tool_get_notifications_settingno sensitive capabilityextension_tool_get_option_groupsno sensitive capabilityextension_tool_get_partition_keyno sensitive capabilityextension_tool_get_plugins_resource_identifiersno sensitive capabilityextension_tool_get_popups_settingno sensitive capabilityextension_tool_get_profile_user_infono sensitive capabilityextension_tool_get_redirect_urlno sensitive capabilityextension_tool_get_scanner_listno sensitive capabilityextension_tool_get_session_rulesno sensitive capabilityextension_tool_get_theme_colorno sensitive capabilityextension_tool_get_ui_languageno sensitive capabilityextension_tool_get_viewsno sensitive capabilityextension_tool_hide_input_viewno sensitive capabilityextension_tool_history_operationsno sensitive capabilityextension_tool_history_parameters_descriptionno sensitive capabilityextension_tool_import_certificateno sensitive capabilityextension_tool_is_allowed_file_scheme_accessno sensitive capabilityextension_tool_is_allowed_incognito_accessno sensitive capabilityextension_tool_is_regex_supportedno sensitive capabilityextension_tool_launch_web_auth_flowno sensitive capabilityextension_tool_listen_certificates_update_requestedno sensitive capabilityextension_tool_listen_signature_requestedno sensitive capabilityextension_tool_mount_file_systemno sensitive capabilityextension_tool_notify_file_system_changesno sensitive capabilityextension_tool_on_navigatedno sensitive capabilityextension_tool_on_request_finishedno sensitive capabilityextension_tool_open_or_closed_shadow_rootno sensitive capabilityextension_tool_open_resourceno sensitive capabilityextension_tool_open_scannerno sensitive capabilityextension_tool_query_idle_stateno sensitive capabilityextension_tool_read_scan_datano sensitive capabilityextension_tool_reload_inspected_windowno sensitive capabilityextension_tool_remove_all_context_menusno sensitive capabilityextension_tool_remove_appcacheno sensitive capabilityextension_tool_remove_browsing_datano sensitive capabilityextension_tool_remove_cacheno sensitive capabilityextension_tool_remove_cache_storageno sensitive capabilityextension_tool_remove_cached_auth_tokenno sensitive capabilityextension_tool_remove_certificateno sensitive capabilityextension_tool_remove_context_menuno sensitive capabilityextension_tool_remove_cookieno sensitive capabilityextension_tool_remove_cookiesno sensitive capabilityextension_tool_remove_declarative_rulesno sensitive capabilityextension_tool_remove_execute_listenerno sensitive capabilityextension_tool_remove_form_datano sensitive capabilityextension_tool_remove_historyno sensitive capabilityextension_tool_remove_indexed_dbno sensitive capabilityextension_tool_remove_local_storageno sensitive capabilityextension_tool_remove_passwordsno sensitive capabilityextension_tool_remove_service_workersno sensitive capabilityextension_tool_remove_web_sqlno sensitive capabilityextension_tool_report_signatureno sensitive capabilityextension_tool_request_pinno sensitive capabilityextension_tool_search_downloadsno sensitive capabilityextension_tool_send_debugger_commandno sensitive capabilityextension_tool_send_key_eventsno sensitive capabilityextension_tool_set_active_audio_devicesno sensitive capabilityextension_tool_set_audio_device_propertiesno sensitive capabilityextension_tool_set_audio_muteno sensitive capabilityextension_tool_set_auto_verify_settingno sensitive capabilityextension_tool_set_automatic_downloads_settingno sensitive capabilityextension_tool_set_camera_settingno sensitive capabilityextension_tool_set_candidate_window_propertiesno sensitive capabilityextension_tool_set_candidatesno sensitive capabilityextension_tool_set_certificatesno sensitive capabilityextension_tool_set_clipboard_settingno sensitive capabilityextension_tool_set_compositionno sensitive capabilityextension_tool_set_cookieno sensitive capabilityextension_tool_set_cookies_settingno sensitive capabilityextension_tool_set_cursor_positionno sensitive capabilityextension_tool_set_default_fixed_font_sizeno sensitive capabilityextension_tool_set_default_font_sizeno sensitive capabilityextension_tool_set_extension_action_optionsno sensitive capabilityextension_tool_set_idle_detection_intervalno sensitive capabilityextension_tool_set_images_settingno sensitive capabilityextension_tool_set_javascript_settingno sensitive capabilityextension_tool_set_location_settingno sensitive capabilityextension_tool_set_menu_itemsno sensitive capabilityextension_tool_set_microphone_settingno sensitive capabilityextension_tool_set_minimum_font_sizeno sensitive capabilityextension_tool_set_notifications_settingno sensitive capabilityextension_tool_set_open_resource_handlerno sensitive capabilityextension_tool_set_popups_settingno sensitive capabilityextension_tool_set_scanner_optionsno sensitive capabilityextension_tool_set_update_url_datano sensitive capabilityextension_tool_show_default_folderno sensitive capabilityextension_tool_start_scanno sensitive capabilityextension_tool_stop_pin_requestno sensitive capabilityextension_tool_test_match_outcomeno sensitive capabilityextension_tool_unmount_file_systemno sensitive capabilityextension_tool_update_context_menuno sensitive capabilityextension_tool_update_dynamic_rulesno sensitive capabilityextension_tool_update_enabled_rulesetsno sensitive capabilityextension_tool_update_session_rulesno sensitive capabilityextension_tool_update_static_rulesno sensitive capability
Toxic flows 1
Cross-tool combinations that form a data-exfiltration primitive (untrusted input → sensitive source → external sink).
What this scan could not see
- Tools were statically extracted from the published source (200 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".
Versions 1
Scan history per published version. The engine is deterministic — the same version always yields the same score, so a changed score means the package itself changed.
| Version | Score | Findings | Engine | Scanned |
|---|---|---|---|---|
v4.0.0 latest |
A 90/100 | 17 | 1.13.0 | 2026-09-07 |
Embed this score
Show this server's live Trust Score in your README, docs or website. The badge is served straight from the registry and updates automatically after every rescan — no API key needed. It links back to this page, so anyone who sees the grade can also read the findings behind it instead of taking a number on faith.
Verify this score yourself
The score above is reproducible: the same package version always yields the same result. Run it locally or over the free API — no account, no LLM, fully deterministic.
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