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

Annotations already flag destructiveHint=true, but the description goes well beyond them: it warns THIS DELETES THE POST and to confirm with the person, and it documents two specific refusal conditions (published/publishing posts are already live; posts in a running hook test would trigger a Lab replacement). That is rich behavioral context that the annotations alone do not convey.

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?

The critical delete warning is front-loaded in the first two sentences, followed by the alternative and the refusal conditions. Every sentence carries distinct, non-redundant information with no filler.

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 single-required-param destructive tool with no output schema and full annotation coverage, the description supplies the confirmation requirement, refusal cases, and sibling routing. Nothing an agent needs to call it safely is missing.

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 coverage is 100% and postId is fully documented in the schema, including the 'with or without dashes' detail. The description adds no parameter-level meaning beyond that, 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 precise verb+resource+scope: cancel and delete a post that has not gone out yet, enumerated as scheduled, draft or failed. It explicitly distinguishes itself from update_post, which handles text/media/time changes, so an agent can separate the two siblings without opening schemas.

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?

Gives explicit when-to-use, when-not-to-use, and the alternative: use update_post to edit a post, and stop a running hook test in the app rather than canceling here. Nothing about routing is left to inference.

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