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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds real value beyond that: it explains the withdrawal side effect (approval links stop working) and the pre-publishing timing limit, which annotations cannot express.

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 compact sentences, front-loaded with the action and states, then the critical timing constraint and side effect. No filler or repetition of the title.

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 mutation with no output schema, the description covers what the tool does, when it is valid, and the user-visible side effect. It stops short of stating what a successful call returns or how an already-cancelled post is handled, though the idempotent annotation partly covers the latter.

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 id parameter, so the schema already carries the meaning. "Takes the id of the scheduled post" restates the schema without adding format, source, or lookup guidance, 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 (cancels/withdraws) and resource (queued, held, or approval-waiting scheduled post), and enumerates the post states it applies to. An agent can distinguish this from schedule_post, list_scheduled_posts, or get_post_status without opening any schema.

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?

"Only works before it starts publishing" gives a clear applicability window, which is the decisive condition for choosing this tool. It does not name an alternative for the post-publish case, but the exclusion is stated clearly enough to route the agent.

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