Send a message

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and openWorldHint=true. The description adds genuinely new behavioral context: the message is 'visible to the recipient immediately' (irreversible external side effect) and 'posts as you' (identity/attribution). It does not mention error cases or that the returned message id feeds reply_to.

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 short sentences, action stated first, caution second. No filler, no repetition of the title.

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 4-parameter send tool with no output schema, the description covers purpose, visibility, and attribution adequately. Minor gap: it doesn't hint that a message id is returned (useful for the sibling reply_to parameter), but nothing essential is missing.

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 description coverage is 100% and all four parameters (peer, text, silent, reply_to) are documented in the schema itself. The description adds no parameter-level detail, so the baseline 3 applies.

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?

Specific verb+resource: 'Send a message to a chat.' An agent can distinguish it from siblings like edit, forward, and send_file by the resource named. It stops short of explicitly contrasting with send_file (file vs text) or forward, but the purpose is unambiguous.

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 closing clause 'only send what was actually asked for' gives an implied usage constraint (don't send unprompted content), but there is no explicit when-to-use guidance and no named alternatives such as edit or forward for modifying/relaying existing messages.

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