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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description adds real behavioral value beyond that: the effect is terminal for the post ('Cancelled posts cannot be rescheduled; a new post is needed instead'). It doesn't say whether the cancel is reversible or how the post's status/returns change, but the irreversibility disclosure is substantive.

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?

Three short sentences, front-loaded with the action, then the precondition, then the consequence. No filler and every sentence carries information.

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 destructive one-param mutation with no output schema, the description covers the action, the eligibility constraint, and the downstream consequence. It leaves the precise resulting state of the post (deleted vs status change) unstated, a minor gap given annotations already signal destructiveness.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents postId fully. The description's mention of 'scheduled post' is consistent with the schema but adds no syntax or format detail beyond it — baseline 3.

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+resource ('Cancel a scheduled post') and immediately scopes it to scheduled posts only, which distinguishes it from the sibling delete_post and edit_post. An agent can tell what this does without opening the 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?

Gives a clear precondition ('Only scheduled posts can be cancelled') that tells the agent when this tool is applicable versus other post-mutating siblings. It stops short of naming an explicit alternative or stating when-not-to-use beyond the scheduled-only restriction.

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