render_cancel_job

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

Annotations declare it is not read-only, not idempotent, and not destructive. Beyond that, the description adds genuine behavioral context: what actually gets stopped and the macOS caveat that the FL renderer may stay open after cancellation. That platform-specific quirk is not derivable from annotations or schema.

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 sentences, front-loaded with the core action and then the caveat. No filler; every clause carries information.

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?

An output schema exists, so return values need not be described, and the description covers the action, side effect, and follow-up status check. It stops short of stating permission or failure conditions, but is essentially complete for a single-parameter cancel tool.

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?

One parameter with 100% schema coverage; the schema already documents job_id, its pattern, and its origin from render_start_job. The description adds nothing further about the parameter, so the baseline 3 applies.

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 (render job) and defines what cancellation actually does: 'stop monitoring it and the process it started.' It references render_get_job for status, which helps orient against the render_* siblings, though it doesn't explicitly contrast render_start_job.

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 the follow-up action (check render_get_job for final status) but never states when to cancel versus other options, nor any preconditions. Usage is inferable from the obvious semantics but not spelled out.

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