close_browser

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It states the action ('close') but does not specify side effects such as whether the action is reversible, what happens to any in-progress operations, or the return value. For a routine that ends a session, details like idempotency or error handling are missing.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, clear sentence that immediately conveys the tool's purpose. It is front-loaded and contains no redundant or extraneous information. It earns its space by being efficiently descriptive.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity and the presence of an output schema, the description is incomplete. It does not mention what the tool returns (e.g., success status), nor does it address edge cases like calling when no browser context is open. With no annotations, more context is needed for a complete picture.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has no parameters and 100% schema description coverage. According to the rubric, when schema coverage is high, baseline is 3 even without parameter info in the description. The description adds no parameter-level meaning since there are none, so a score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Close the persistent browser context for the current MCP server process.' It uses a specific verb (close) and resource (persistent browser context), and the action is distinct from sibling tools like click, fill, or browser_auth_status which handle interactions or authentication.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not provide any guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., if a browser context must be open), nor does it explain when it is appropriate to close the browser (e.g., after a series of steps). Sibling tools like 'use_browser_session_token' or 'browser_auth_status' have overlapping contexts, but no differentiation is given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.