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

Goes well past the annotations: the resulting status, the fact that the original send time is preserved, that no publish occurs, and that the action is reversible via rescheduling with all limits rechecked at that time. That last point is important behavior an agent would not infer from destructiveHint=true alone, and it does not contradict the annotations.

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?

Front-loaded with the action, then the state definition, then the observable effects and the reversal path. Every sentence adds information; nothing restates the title or the annotations.

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, idempotent state-change tool with an output schema already present, the description covers what an agent needs: what changes, what is preserved, and how to undo it. Return values need not be explained given the output schema.

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%, though the schema text for post_id is only 'the post id'. The description adds an implicit constraint that the referenced post must be in a scheduled or plan_hold state, which is modest value beyond the schema. With the schema carrying the field definition, 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 ('call off') and resource ('scheduled post'), and covers the secondary state ('plan_hold') the tool also operates on. It implicitly separates itself from delete_post by noting the time slot is retained and nothing is published, so an agent can distinguish the two without opening either 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 clear context for when this is the right call: the post is scheduled or frozen on plan_hold, and the user wants it not to publish while keeping the calendar slot. It also names the recovery path (schedule it again). It never explicitly names delete_post as the alternative when the slot should be removed, so a small inference is left to the agent.

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