Cancel scheduled message

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

Annotations already signal a non-read-only operation. The description adds that only pending messages can be canceled, which narrows the scope, but it does not disclose potential errors, irreversibility, or permission requirements. Minimal extra context beyond 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?

The description is a single short sentence that immediately states the action and object, with no filler words or redundant details.

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 simple cancel operation with two parameters and no output schema, the description provides enough context about the action and its prerequisite (pending message id). The lack of output schema is acceptable for a fire-and-forget cancellation, though it could mention behavior for nonexistent or already-sent IDs.

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?

The schema documents 'guild' with a description, but 'schedule_id' has only a type. The description's 'by its id' clarifies the role of schedule_id but adds little beyond the schema. The 50% schema coverage is not fully compensated, though the simple nature of the parameter makes it adequate.

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?

The description uses a specific verb 'cancel' and identifies the resource as a 'pending scheduled message' with the required identifier. This clearly distinguishes it from sibling tools like schedule_message and list_scheduled_messages.

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?

The description implies the tool is for canceling messages that have not yet been sent and that an ID is required, but it does not explicitly reference list_scheduled_messages for obtaining the ID or state when not to use. Guidance is implied rather than explicit.

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