send_message

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

With no annotations supplied, the description carries the full behavioral burden, and it does disclose the key trait: non-blocking by default, blocking up to roughly 55 seconds when wait_seconds > 0. It says nothing about queuing semantics, what happens if the agent is busy or stopped, or what is returned on a blocking timeout, which are the decisions an agent actually needs.

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 with the core action first and the blocking caveat second; there is no filler and the important operative detail (wait_seconds behavior) is front-loaded rather than buried.

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 three-parameter mutation tool with no annotations and no output schema, the definition covers the blocking contract but leaves the return value undefined (

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 compensate for three undocumented parameters. It adds real meaning for wait_seconds (default-immediate behavior plus an approximate 55-second ceiling, which the schema does not convey), but agent_id and text receive no clarification at all, leaving a clear gap.

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 uses a specific verb plus target ("Send the agent its next instruction"), which clearly separates it from file-transfer siblings like send_files and control siblings like interrupt_agent. It doesn't name any sibling explicitly, and "instruction" is slightly ambiguous versus a plain chat message, so it falls short of a 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?

Usage is only implied: setting wait_seconds > 0 signals the blocking/poll use case, and the sibling set implies this is the way to drive an already-spawned agent. There is no explicit statement of when to prefer send_message over interrupt_agent, wait_for_agents, or spawn_agent, and no prerequisites or error conditions are given.

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