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

Annotations are minimal (readOnlyHint=false, destructiveHint=false) and the description adds useful behavior: it blocks, and it clarifies that `changed: false` is a legitimate return, not an error. This goes beyond the schema and annotations, giving the agent expectations about timeout and empty results. It does not contradict the annotations.

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 redundancy. The primary purpose is stated first, followed by a rationale and a behavioral caveat. Every sentence earns its place, and the description is front-loaded with the core action.

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 no output schema, so the description should explain the return value. It mentions `changed: false` but does not describe other potential return fields or timeout behavior beyond the parameter bounds. It also assumes familiarity with 'bus' and 'window' without defining them, which could confuse an agent. Given the simplicity of the tool, it is adequate but not fully 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 both parameters (cursor and max_seconds), so schema coverage is 100%. The description does not add any new meaning about the parameters; it only implies they control the wait, which the schema already conveys. Baseline 3 is appropriate.

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 a specific verb and resource: it blocks until the bus moves past the cursor or the window passes. This distinguishes it from sibling tools like get_feed or get_board, and the title and name align. The purpose is unambiguous and not a tautology.

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 recommends this over a fixed timer ('Prefer this to a fixed timer') and explains the downside of polling. It does not, however, state explicit conditions for when NOT to use it (e.g., when you need immediate results or cannot block), so it is not a full 5. Still, the guidance is clear and actionable.

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