receive_messages

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

With no annotations, the description fully bears the responsibility for behavioral disclosure. It mentions storing messages locally and polling without returning results in the call, which covers the key behavioral trait. However, it could further clarify that messages are stored for later retrieval and what happens on timeout, but it is still strong.

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 zero wasted words: first sentence states the action, second provides usage context and alternative. Highly efficient for a simple tool.

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?

Given the tool's simplicity (one optional parameter, no output schema) and the strong sibling alternative, the description covers the core behavior and usage context. It omits details about return value (e.g., success/failure), but since the tool stores messages and does not return them, a brief mention of the response format would improve completeness. Still, it is sufficient for the agent to use correctly.

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?

Input schema coverage is 100%, so the schema already documents the timeout parameter with description and default. The tool description adds no new parameter meaning beyond recontextualizing the polling action. Per guidelines, baseline 3 is appropriate when schema covers parameters.

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 clearly states the tool's function: manually poll signal-cli for new messages and store them. It distinguishes itself from the sibling tool get_unread by specifying that receive_messages is for polling without reading results, making the purpose 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?

Explicit usage guidance is provided: prefer get_unread for automatic polling with results in one call, and use receive_messages only when you want to poll without immediately reading results. This helps the agent decide between siblings.

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