send_message

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

No annotations are provided, so the description carries the full burden. It only says 'Send a message,' which implies a write operation, but it does not disclose any behavioral traits such as side effects, authentication requirements, rate limits, or whether the message is actually sent (e.g., confirmation). This is insufficient for a mutation tool.

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 sentence of 13 words, which is appropriately concise and front-loaded. It communicates the essential purpose without unnecessary detail. However, it could potentially include a bit more context without becoming verbose.

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 has 5 parameters and no output schema or annotations, the description is too minimal. It does not explain what happens after sending (e.g., return status, error handling), nor does it provide formatting expectations for the message content. A tool of this complexity requires more detail to be fully 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?

The input schema has 100% coverage with descriptions for all 5 parameters. The description does not add any extra meaning beyond what is already in the schema. Per guidelines, with high schema coverage, the baseline is 3, and the description meets this baseline without adding value.

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 ('message'), and gives a specific example ('email with formatted content'). However, it might be interpreted as supporting multiple message types, while the schema only allows 'email'. Sibling tools include social media tools like 'post_to_bluesky', but no other email tool, so it is distinct.

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 no guidance on when to use this tool versus alternatives. No explicit when-to-use, when-not-to-use, or alternative tools are mentioned. Given the lack of context, the agent would have to infer usage from the tool name and schema alone.

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