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

Annotations already indicate a non-read-only mutation. The description adds that authentication is required, which is not in annotations. It doesn't detail side effects like notifications or rate limits, but given the simple nature, this is 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, front-loaded with the action, and includes necessary context in a compact way.

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 two-parameter tool with no output schema, the description covers the main usage, authentication, and chat_id source. It doesn't mention success/failure behavior, but that might be inferred from standard API responses.

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 description explains that chat_id is the same id from get_my_requests or accept_quote, which adds semantic meaning beyond the schema. It doesn't explain text, but text is self-explanatory.

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 'send' and resource 'chat message', and specifies the context 'into an existing Tewdy thread'. It distinguishes from siblings which are about quotes/requests, not messaging.

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?

It provides context on when to use (typically after quote submitted/accepted) and where to obtain chat_id. It doesn't explicitly mention when not to use, but given no other messaging tools, the guidance is adequate.

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