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

Annotations already declare destructive=true, idempotent=true, and readOnly=false, so the safety profile is covered. The description adds a genuine behavioral consequence beyond that: '(credits released)', telling the agent the cost side-effect of cancelling. It does not cover error behavior for already-finished videos.

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?

A single tight sentence that front-loads the action and appends the side effect in parentheses. No wasted words.

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 one-parameter cancel operation, annotations cover the safety profile and the description adds the credit-release consequence. With no output schema, an agent still lacks guidance on what happens if the video is already complete or how success is reported, but the coverage is solid for this complexity level.

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% for the single video_id parameter, so the schema already carries the parameter meaning. The description adds nothing about the id format or constraints, 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 and resource ('Stop a ... video') and scopes it to 'queued or processing' work, which distinguishes it from other video tools. It does not name sibling alternatives like delete_video or retry_video, so an agent must infer the boundary itself.

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 processing' implicitly tells when the tool applies (only in-flight jobs), which is useful state guidance. However, there is no explicit when-not guidance and no mention of related siblings such as delete_video or retry_video, so the routing decision is only implied.

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