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

Annotations already declare destructive=true and idempotent=true, but the description adds real behavioral detail the annotations cannot express: cancellation is conditional on the post being editable and is refused for publishing or uncertain-delivery posts. The terms 'safely editable' and 'uncertain delivery' are left undefined, which keeps this from a 5.

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, front-loaded with the action and then the guard condition; nothing is wasted. The qualifier 'only while safely editable' overlaps somewhat with the second sentence's exclusion, a minor redundancy.

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?

An output schema exists, so return values need no explanation, and the annotations cover the safety profile. However, for a destructive mutation with fully undocumented parameters, the description omits idempotency semantics and what error/refusal behavior the agent should expect when the guard rejects the cancel.

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 0%, so the description carries the full burden for three parameters. It only gestures at 'the expected post revision' (implying an optimistic-concurrency match against the revision param) and says nothing about postId or the required idempotencyKey, leaving most parameter meaning undocumented.

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 resource (the expected post revision), plus a scope constraint (only while safely editable). It is clearly distinguishable from siblings like update_campaign_post or validate_post, though it never names an alternative operation by name.

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 both a positive condition ('only while safely editable') and a negative exclusion ('never cancels a post already publishing or with uncertain delivery'), which is more than most definitions offer. It stops short of naming the sibling tool to use instead when cancellation is refused.

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