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

Goes beyond the annotations by disclosing a real side effect (reserved credits are returned) and the post-condition that completed exports are unaffected. Idempotency is restated in prose, which reinforces rather than contradicts idempotentHint=true. It still omits what happens if the job is not owned or already finished.

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, each carrying distinct information: the action, the credit consequence, the effect on completed exports, and the idempotency guarantee. The core action is front-loaded and nothing is padding.

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?

With an output schema present, return values need no explanation, and the description covers preconditions, side effects, and idempotency for a single-parameter tool. The remaining gap is not telling the agent how to obtain a valid jobId or what error surfaces for a non-owned job.

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%, so the description carries the burden for jobId, and it says nothing about it beyond the implied context of a render/export job. The parameter is largely self-explanatory by name and uuid format, but the description never says where the identifier comes from (e.g. render_video or list_renders).

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?

Names a specific verb (cancel) and a specific resource (an owned pending or running cloud export), and scopes it to the states where cancellation is meaningful. This clearly separates it from render_video (create), list_renders/read_render (inspect), and wait_for_jobs (observe) among siblings.

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?

Clearly states the conditions under which cancellation is valid (pending or running, owned) and implicitly signals when not to bother (completed exports remain available). It does not name a sibling tool the agent should reach for in a related situation, so it stops short of full alternative routing.

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