send_message

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

No annotations are provided, so the description must disclose behavior. It warns about sending real messages (destructive action) and explains parameter constraints. However, it omits details like rate limits, delivery confirmation, character limits, or logging. The return value is only briefly mentioned.

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 concise and well-structured. It starts with a clear purpose, includes a necessary warning, then lists parameters in a readable format. Every sentence adds value, and there is no redundancy.

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?

The tool has 3 parameters and no annotations. The description explains parameters well but does not detail the output format beyond 'Success or error message'. Context indicates an output schema exists, which may compensate, but the description doesn't elaborate on error handling or idempotency. For a mutation tool, more completeness would be beneficial.

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 0%, so the description must explain parameters. It does so effectively: recipients are comma-separated and must match exactly, body is the message text, and school is a subdomain required for disambiguation. This adds essential meaning beyond the schema.

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'), the resource ('message'), and the target ('one or more Edupage users'). It also includes a warning about the action being real, which adds context. Among siblings, there are only read-only 'get_' tools, so this tool 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 warns that this sends real messages, implying careful use. It explains the exact match requirement for recipients and the school subdomain when ambiguous. However, it does not explicitly state when not to use this tool or suggest alternatives (though none exist among siblings).

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