Cancel full decode

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

Annotations already declare readOnly=false, destructive=false and idempotent=true, so the safety profile is covered. The description adds real value beyond that by bounding the blast radius: only the owned FFmpeg verification child is affected, exports and media survive. It stops short of saying what the job's resulting status is or what happens if no verification is running.

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, no filler. The affirmative scope comes first and the exclusions second, which is the right order for an agent that has already chosen this tool.

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?

No output schema exists, so the description would need to convey the post-cancellation outcome, and it doesn't — an agent cannot tell whether the call returns a status, throws when nothing is running, or leaves the job in a terminal state. For a one-parameter mutation with annotation coverage the bar is lower, but the gap on job_id meaning and result state keeps this at minimum-viable.

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?

There is one required parameter (job_id) with 0% schema description coverage, so the description must carry the semantics. It says 'this session's' which hints at scoping but never clarifies that job_id is the verification job identifier rather than an export or window id — a meaningful ambiguity given the uuid format constraint.

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 a precisely scoped resource (this session's owned FFmpeg verification child only), and immediately names what it does not touch (Studio exports, media). The phrase 'verification child' is slightly jargon-dependent, but combined with the title 'Cancel full decode' an agent can distinguish it from studio_verify_export and studio_export_checkpoint.

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 negative scoping ('does not cancel Studio exports or delete media') implicitly tells the agent this is not the tool for stopping exports, which is useful routing. However, it never states the positive trigger condition — e.g. when a verification is running and you want to abort it — nor points to a sibling for the excluded cases, so the agent must infer usage from context.

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