send_peer

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

With no annotations, the description carries the behavioral burden and does well: it discloses fire-and-forget semantics, when the function returns, and the peer's independent-agent limitation. This is meaningful behavioral context beyond a simple 'send' description. The only minor gap is unspecified error/return details, which are peripheral for a fire-and-forget call.

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?

Three sentences, each earning its place: first states the operation, second defines the async behavior, third gives naming guidance and the peer limitation. There is no filler, redundancy, or restatement of schema content.

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 5-parameter tool with no output schema and no annotations, this definition is nearly complete. The description explains return timingarena, the schema documents all parameters, and the naming guidance ties to the sibling peers tool. The one missing piece is what the return payload contains (e.g., a message id for in_reply_to), but the fire-and-forget framing makes this low-risk.

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%, so the baseline is 3. The description adds value by explaining that peer names come from the peers tool and that an unambiguous prefix is accepted, which is more actionable than the schema's examples. It also reinforces that the message is sent verbatim, aligning with 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 opens with a precise verb and resource: 'Send a text message to a live Claude Code session on this machine.' It is immediately distinct from the sibling peers and message_log tools, which list peers and read logs rather than send. The fire-and-forget clarification further pins down the tool's purpose.

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 practical usage context: 'Use the name from peers; an unambiguous prefix works' tells the agent how to construct the peer parameternail. It also states an important exclusion — 'The peer is another agent with its own human — it cannot approve anything for you' — guiding when not to use this tool for approvals. It does not explicitly mention sibling tools as alternatives, but the usage context is clear.

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