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

Annotations are empty, so the description carries the full burden. It discloses the key side effect (stops driving the phone between steps) and the no-op behavior for not-yet-started jobs. It does not clarify the end state of the submission record (deleted, marked cancelled, etc.), but the disclosed behavior is valuable beyond the name.

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, zero fluff, and the core action is front-loaded. The behavioral clarification follows naturally. Every word earns its place.

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 one-parameter tool with no output schema, the description covers the action and key behavior. It omits error conditions (e.g., submission not found, already completed) and return values, but those are less critical for a cancellation operation. Overall, it is adequately complete.

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 the schema already explains the parameter ('ID of the submission to cancel, on any platform'). The description adds no extra semantic detail beyond what is in the schema, so the baseline of 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?

Clearly states the specific verb 'cancel' and resource 'video submission', names the supported platforms (TikTok, Instagram, YouTube), and distinguishes from siblings by focusing on the cancellation of queued/in-flight jobs. The description adds nuanced behavior (no-op for not-started) that makes the tool's purpose unambiguous.

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?

Provides clear context for when the tool applies (queued or in-flight submissions) and explicitly states the not-yet-started case no-ops, which is a de facto exclusion. However, it does not explicitly compare to alternative tools like delete-submission or mention when to use them instead, so it stops short of full guidance.

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