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

While annotations already declare destructiveHint=true and idempotentHint=true, the description adds critical behavioral nuance: already-publishing destinations cannot be recalled and are returned in still_going, and it confirms idempotency with 'Safe to call again.' This goes beyond the hints and provides operational expectations.

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 tightly written sentences. The main action is front-loaded ('Stop a post before it goes out'), followed by essential behavioral details. No filler or redundant phrasing.

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?

Given the output schema exists (so return values are defined elsewhere) and the description covers cancellation semantics, partial behavior, and idempotency, an agent has everything it needs to call the tool correctly. The description is complete for a destructive action.

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?

The input schema already documents post_id with 'From posts_list,' and schema coverage is 100%. The description does not add any additional meaning or format details for the parameter, so it relies entirely on the schema.

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 opens with a specific verb and resource ('Stop a post') and then clarifies the exact behavior (destinations not started are cancelled; already-publishing ones are returned in still_going). This clearly distinguishes it from siblings like posts_schedule and posts_update, which create or modify posts.

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 (to cancel a scheduled post) and describes the partial-cancellation behavior, but it does not explicitly name alternatives or state when NOT to use it. The context is clear enough for an agent to infer, but explicit exclusion would elevate it to a 5.

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