Public assessment

browsermcp/mcp (@browsermcp/mcp)

browsermcp-mcp · v0.1.3 · scanned Aug 2, 2026

What changed in the harness

Selection accuracy 95→95, token cost up 16%, unconfirmed writes 0%→0%.

Category breakdown

Where the score comes from.

Earned points across the four signals Gradable measures. Safety and Legibility are scored out of 30; Economics and Discoverability are scored out of 20.

01Safety

0.0 / 30

0.0 out of 30

02Legibility

24.6 / 30

24.6 out of 30

03Economics

20.0 / 20

20.0 out of 20

04Discoverability

11.5 / 20

11.5 out of 20

Highest-impact fix

Estimated gain +30 points

Add explicit identity and permission preflight tools

Expose machine-readable principal/tenant confirmation and a non-mutating permission check so agents can verify both before destructive actions.

Description evidence

Defects and rewrites.

12 defects found across the exposed tool descriptions. Suggested rewrites make purpose, inputs, boundaries, and returns easier for an agent to understand.

Tool	Defect types	Suggested rewrite
`browser_navigate`	no_return_description	Navigate the current browser tab to the given URL and wait for the page to load. Returns the resulting page state (e.g. URL/title or an accessibility snapshot) after navigation completes.
`browser_go_back`	no_return_description	Navigate the browser back to the previous page in history. Returns the resulting page state (e.g. URL/title) after the navigation completes.
`browser_go_forward`	no_return_description	Navigate the browser forward to the next page in history. Returns the resulting page state (e.g. URL/title) after the navigation completes.
`browser_snapshot`	no_return_description	Capture an accessibility snapshot of the current page, returning a structured tree of elements with reference IDs that can be used to target elements for interaction (click, type, hover, etc.).
`browser_click`	no_return_description	Perform a mouse click on the specified element identified via a page snapshot reference. Returns confirmation of the click along with the resulting page state or updated snapshot.
`browser_hover`	no_return_description	Move the mouse to hover over the specified element identified via a page snapshot reference, triggering any hover-based UI (tooltips, menus). Returns confirmation of the action along with the resulting page state.
`browser_type`	no_return_description	Type the given text into the specified editable element identified via a page snapshot reference, optionally pressing Enter afterward if submit is true. Returns confirmation of the input along with the resulting page state.
`browser_select_option`	no_return_description	Select one or more option values in the specified dropdown element identified via a page snapshot reference. Returns confirmation of the selection along with the resulting page state.
`browser_press_key`	no_return_description	Simulate pressing a single keyboard key or character (e.g. 'ArrowLeft', 'a') on the currently focused element. Returns confirmation that the key press was dispatched along with the resulting page state.
`browser_wait`	no_return_description	Pause execution for the specified number of seconds before continuing, useful for waiting on page transitions or animations. Returns confirmation once the wait period has elapsed.
`browser_get_console_logs`	name_restates_behavior no_return_description	Retrieve the browser's console output (logs, warnings, and errors) accumulated since the page loaded or since logs were last cleared. Returns an array of console log entries with their severity level and message text.
`browser_screenshot`	no_return_description	Capture a screenshot image of the current state of the browser page. Returns the screenshot as image data (e.g. base64-encoded PNG).

Selection evidence

Confusable tool pairs.

4 pairs where similar names or overlapping descriptions may send an agent toward the wrong tool.

Tool A	Tool B	Confidence	Why they collide
`browser_go_back`	`browser_go_forward`	high	Both take no parameters and mean directional page navigation; a vague task like 'go to the previous page' vs 'return to where I was' can be misread, and 'back'/'forward' semantics are easy to invert when inferred from ambiguous phrasing (e.g. 'undo that navigation').
`browser_snapshot`	`browser_screenshot`	high	Both capture the current page state; a task like 'show me the page' or 'capture what's on screen' could be satisfied by either, but snapshot returns accessibility refs for interaction while screenshot returns a visual image—agent may pick the wrong one depending on whether it conflates 'look at the page' with 'get element references'.
`browser_click`	`browser_hover`	medium	Both act on an element via element+ref and are used to 'interact with' something; a task like 'trigger the dropdown menu on the nav item' could be satisfied by hover (to reveal) or click depending on site behavior, and phrasing like 'select that button' is ambiguous between hovering to inspect and clicking to activate.
`browser_click`	`browser_type`	low	Both target an element via ref for interaction, but click has no text parameter while type requires text and submit; a task like 'fill in and submit the search box' is unambiguous enough that confusion is unlikely, though 'interact with the field' phrasing could momentarily blur the choice.

Compare the field

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