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

No annotations are provided, so the description bears full responsibility. It discloses that the tool performs a partial update (only passed fields change). It does not mention side effects, permissions, or idempotency. For a mutation tool, this is minimal but acceptable.

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?

Two sentences with no waste. The first sentence states the action, the second adds important nuance and a usage tip. Every sentence 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?

With no output schema, the description does not explain the return value. It covers the essential behavior (update existing message, partial update) but lacks details on response format or error conditions. Given the tool's simplicity, it is adequate but not complete.

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 detailed field descriptions. The description adds value by clarifying partial update semantics and providing context for the suggested_message_id parameter ('Get the id from list_suggested_messages').

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' and the resource 'existing suggested message'. It also distinguishes from list_suggested_messages by referencing how to get the ID, and from add_suggested_message by implication (create vs update).

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 provides clear guidance: use to update an existing suggested message, and retrieve the ID from list_suggested_messages. It also notes that only passed fields are changed (partial update). However, it does not explicitly state when to use this tool versus alternatives like add_suggested_message, but the context makes it clear.

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