wait_for_message

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

With no annotations, the description carries the transparency burden. It discloses the long-polling (blocking) behavior, the timeout condition ('empty after `seconds`'), and the triggering condition ('message newer than `since`'). It does not cover error scenarios or exact response structure, but the core behavior is well described.

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?

The description consists of two packed sentences: the first defines the functional behavior, and the second gives usage guidance. Every word serves a purpose, making it exceptionally concise and well-structured.

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 description combines parameter context, response semantics (message or empty after timeout), and performance trade-offs. Without an output schema, it clearly explains what the caller can expect. It lacks details like error handling or response payload format, but for a simple long-poll with three parameters, this is sufficiently complete.

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?

The input schema already provides full descriptions for all three parameters (100% coverage). The description adds minimal contextual meaning by referencing `since` and `seconds` in the behavior explanation, but it does not significantly deepen parameter understanding beyond the schema, so the baseline of 3 applies.

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 'Long-poll a room,' which clearly identifies the verb and resource. It distinguishes itself from siblings by specifying it waits for a message newer than `since` and returns empty after `seconds`, unlike read_room or say.

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 explicitly states 'Cheaper and faster than repeated reads — prefer this over polling.' This names an alternative (repeated reads) and gives a clear preference directive, telling the agent when to choose this tool over other read strategies.

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