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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is known. The description adds genuinely new context: the blast radius is bounded ('work already done on websites is not undone') and repeat calls on finished tasks are no-ops, which sharpens the idempotency claim with concrete behavior.

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?

Three short sentences, front-loaded with the action and effect, then the two behavioral caveats. Nothing is redundant or padded.

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 one-parameter, no-output-schema tool whose annotations cover safety, the description supplies what matters: the resource released and the non-destructive scope. Missing only the task_id provenance and error behavior on an unknown id.

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 0% and the single parameter task_id is never mentioned in the description, so nothing tells the agent where the id comes from (task_state, browser_run output) or what format it takes. This is the one part of the definition the schema does not carry.

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 and resource ('Cancel a BrowserPair task') plus the concrete side effect ('release the user's browser'). The cancel verb cleanly separates it from the read/inspect siblings (task_state, task_observe, task_diagnostics) without needing to open any schema.

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?

Gives clear context for when to call it (to stop a task and free the browser) and implicitly covers the repeat-call case with 'Already-ended tasks stay as they are'. It does not name an alternative tool or state any exclusion, so it stops short of full routing guidance.

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