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 behavioral burden, and it does not say whether the message is delivered synchronously or queued, whether it persists, what happens if the recipient is offline, or whether it requires authorization. Only the schema reveals that 'to' defaults to all. This is a significant gap for a cross-agent messaging 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?

A single front-loaded sentence with no filler; the enumerated intents earn their place. It is efficient, though brief enough that it leaves obvious context gaps unaddressed.

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?

With no annotations, no output schema, and a minimal description, an agent cannot tell delivery semantics, failure modes, or how this differs from update_status/read_messages. For a messaging primitive in a multi-agent bridge, the definition is under-specified relative to its complexity.

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 the schema already documents all three parameters, including the recipient enum values and the 'all' default; the description adds no parameter-level meaning beyond it. Baseline 3 applies when the schema does the heavy lifting.

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 gives a specific verb+resource (leave a message for the other party) and enumerates the four intents (ask, hand off, notify, reply), so the purpose is clear. It does not name or contrast with the obvious sibling read_messages, so it lands at 4 rather than 5.

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 intent list (question, handoff, notification, reply) implies when this tool is appropriate, which is more than nothing. However there is no explicit when-not-to-use, no mention of read_messages as the read-side counterpart, and no stated prerequisites, leaving routing to inference.

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