update_channel_message

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

Annotations show readOnlyHint=false, destructiveHint=false, idempotentHint=true. The description adds the behavioral constraint 'Only the body can be modified', which is useful. However, it omits possible side effects (e.g., notifications), error conditions, or required permissions. The annotations already cover idempotency, so the description provides marginal extra transparency.

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 eight-word sentence with zero redundancy. It front-loads the purpose and constraint, making it immediately actionable for an AI agent. Every word earns its place.

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?

Given the tool's simplicity (three parameters, all strings) and the presence of an output schema, the description covers the essential operation and constraint. It does not explain return values or error handling, but the output schema likely handles that. Overall, it is adequately complete for this level of complexity.

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% with generic descriptions ('a string that will be trimmed'). The description adds semantic value by stating that only the 'body' parameter is modifiable, clarifying the role of the other two parameters (channel and messageId) as identifiers. This surpasses the schema's information.

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 clearly states the verb 'Update', the resource 'channel message', and the specific constraint 'Only the body can be modified.' This distinguishes it from siblings like send_channel_message (create) and delete_channel_message (delete), leaving no ambiguity.

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 when to use (when updating the body of an existing message) but lacks explicit guidance on when not to use it or any prerequisites (e.g., ownership or permissions). No alternatives are mentioned, though the context is clear among siblings.

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