Cancel Scheduled Message

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

The description adds the context that the message was previously scheduled, which implies a future send that can be cancelled. It does not elaborate on side effects or permanence, but the annotations already indicate this is an idempotent, non-read-only, non-destructive operation.

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 focused sentence with no redundant words, quickly conveying the tool's purpose.

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 tool with one well-described parameter and annotations covering safety, the description is sufficient and not missing essential return-value information since no output schema is expected.

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 input schema has 100% coverage for the single parameter 'messageId', and the description does not add any additional meaning beyond the schema's own description.

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 the specific verb 'cancel' and identifies the resource as a previously scheduled message, clearly distinguishing it from related tools like send_message or update_event.

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 gives clear context for when to use this tool (to cancel a previously scheduled message) but does not explicitly state when not to use it or mention alternative tools. It lacks exclusions or comparisons.

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