browser_close

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the write/non-destructive profile is covered. The description adds genuinely new context — that closing releases 'all associated resources, including the concurrency slot' — which tells the agent about a quota/rate-limit effect not visible in the structured fields.

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?

A single front-loaded sentence with no filler; the most important fact (closing frees resources and the concurrency slot) is stated immediately.

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?

For a simple one-parameter teardown tool with a rich schema and clear safety annotations, the description is nearly complete. Minor gaps remain — no error/idempotency behavior if the session is unknown or already closed — but nothing essential is missing.

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?

Schema description coverage is 100%; the single session_id parameter is already documented as 'Session ID returned by browser_navigate'. The description adds nothing beyond the schema, so the baseline 3 applies.

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?

States a specific verb (Close) and resource (a browser session), plus the side effect of freeing resources. It is unmistakable against siblings, though it does not explicitly name a counterpart tool the way the highest-scoring examples do.

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?

Usage is only implied — the mention of freeing 'the concurrency slot' hints at when to call it (when you are done and need to release capacity), but there is no explicit when/when-not guidance or named alternative. Neither does it say whether it is safe to call on an already-closed session.

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