Cancel a large-file job

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

Annotations already carry the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, closedWorld), so the description need only add context. It does add which jobs are cancellable, but says nothing about what happens to partial results, whether cancelling a completed job errors, or what the call returns. There is mild tension between "Stops" and readOnlyHint=true, but the idempotent/non-destructive framing is consistent, so this reads as a control-plane action rather than a flagrant contradiction.

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 scope qualifier is attached directly to the action. Slightly too terse for a tool with real edge cases, but nothing is wasted.

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 control tool with no output schema and no parameter descriptions, the description leaves the agent guessing about the outcome: does cancelling discard results, does it return a final status, and how should an already-complete job be handled? The bare annotation set does not cover these, so the gaps are meaningful.

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 coverage is 0%, so the description must compensate for the undocumented job_id. It partially does by implying job_id is the identifier returned by the tool that answered STILL RUNNING, which is useful provenance, but it gives no format, validity, or error semantics for that parameter.

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 ("Stops a background job") plus a scope qualifier (only jobs started by a tool that answered STILL RUNNING). An agent can distinguish it from the read-only job_status sibling, though the description never names that sibling explicitly.

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 phrase "started by a tool that answered STILL RUNNING" gives a usable trigger condition for invocation, implying the job_id came from that prior response. However, there is no when-not guidance (e.g., job already finished), no mention of the job_status alternative for polling instead of cancelling, and no stated preconditions.

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