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

With no annotations supplied, the description carries the full burden, and it does add one genuinely useful behavioral fact: cancellation is refunded if the job has not yet reached the provider. It leaves significant gaps, though — what happens to a job already at the provider, whether cancelling an already-finished job errors or is a no-op, idempotency, and required permissions are all undisclosed.

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?

Two short sentences with zero filler, leading with the action and following with the material consequence. Nothing is redundant or buried.

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 single-parameter mutation with no annotations and no output schema, the description covers the main outcome but omits the return shape (does it return job status, a refund amount, or nothing) and the error/edge-case behavior, which an agent needs before invoking an irreversible action.

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% for the single required parameter generationJobId, and the description adds nothing about its format or where to obtain it (generation.list or generation.status would be the obvious sources). The parameter name is largely self-explanatory, which prevents a 1, but the description does not compensate for the coverage gap.

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 (cancel) and resource (generation) and narrows the scope to jobs that are 'queued or running', which separates it from generation.list and generation.status in the sibling set. It does not explicitly name an alternative, so it stops short of a 5.

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 'queued or running' implicitly tells an agent which job states are eligible for cancellation, but there is no explicit guidance on when to use this versus generation.status or render.delete, and no stated prerequisites such as needing to look up the job ID first.

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