chat_message

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose the side effect of creating a new participant thread on the first message, which is valuable. However, it does not mention error conditions, whether the operation is idempotent, permission requirements, or specifics about the response format beyond the vague 'get the AI facilitator response.' This is adequate but has clear gaps.

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 sentences with no redundant content. The first sentence states the primary action and outcome, and the second adds a key side effect. Information is front-loaded and very efficient.

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 4 parameters, no output schema, and no annotations, yet the description provides a complete enough picture for a simple messaging tool. It explains the action, the response, and the thread-creation behavior. It could go further by describing the response structure or error handling, but given the low complexity, the description is largely sufficient.

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%, so the baseline is 3. The description does not add any parameter-specific meaning beyond what the schema already provides; it only names content, session_id, participant_id, and participant_name in passing. There is no additional syntactic or contextual detail, so the schema fully carries the parameter semantics.

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 ('Send') and resource ('Harmonica session conversation') and clearly states the tool's action and outcome: sending a message and getting the AI facilitator response. The additional detail about creating a new participant thread on first message differentiates it from sibling tools like get_responses or list_sessions.

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 clearly implies when to use the tool: to send a message in a session and receive the facilitator's response. It does not explicitly name alternatives or exclude other tools, but the context is clear enough for an agent to select it for message-sending tasks. No exclusions are stated, so it falls short of a 5 but meets the 'clear context' bar.

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