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

Annotations already indicate readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds the state constraint (queued or running) and the credit-saving rationale, which is useful. However, it does not disclose what happens on cancel (e.g., whether credits are refunded or if cancellation is irreversible), but the output schema may cover return values.

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?

The description is a single, front-loaded sentence that conveys the core purpose and key scope without any fluff. Every word earns its place, making it highly concise and well-structured.

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 cancellation tool with good schema coverage, annotations, and an output schema, the description is nearly complete. It specifies the applicable states and the rationale, though it could explicitly mention side effects or edge cases (e.g., cancelling an already-finished job). Minor gap, but overall adequate.

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%, and both parameters (jobId and workspaceId) have detailed descriptions in the schema. The tool description adds no additional parameter-level information beyond the schema, so the baseline score of 3 is appropriate.

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?

The description uses a specific verb ('Cancel') with a clear resource ('generation job') and adds meaningful scope ('queued or running generation before it finishes spending credits'). This clearly distinguishes it from sibling tools like generation_jobs_get and the various generation creation tools.

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 description implies when to use the tool: when a generation job is queued or running and you want to avoid spending credits. It specifies the applicable states ('queued or running') but does not explicitly name alternatives or exclusions, though the scope is clear enough.

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