Cancel a post that is still pending or queued, so it never publishes. Posts that are already publishing or published cannot be cancelled, and a cancelled post cannot be re-queued — it must be scheduled again. To change a post instead, use update_post. Confirm with the user first.
| Name | Required | Description | Default |
|---|---|---|---|
| post_id | Yes | Post UUID — from list_posts. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already flag destructiveHint=true and idempotentHint=true, but the description adds what those hints do not: the state preconditions that gate cancellation and the fact that cancellation is terminal and cannot be undone by re-queueing. It also adds a user-confirmation requirement, which no annotation conveys.
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 tightly written sentences, front-loading the core action before the constraints, alternative, and confirmation. No sentence is redundant.
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-parameter terminal mutation with no output schema, the description covers scope, preconditions, irreversibility, the sibling alternative, and the confirmation step. Nothing an agent needs to invoke it correctly 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 description coverage is 100% and the single parameter (post_id) is already documented as a UUID sourced from list_posts. The description adds no parameter-level detail, so the schema bears the burden and 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 (cancel) and resource (a post), with the exact scope of what qualifies: 'still pending or queued, so it never publishes.' It also names update_post as the sibling for a different intent, letting an agent route without opening other 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 (pending or queued), when-not (already publishing or published), the irreversible consequence (cancelled posts cannot be re-queued and must be re-scheduled), the alternative for a different intent (update_post), and a confirmation prerequisite.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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