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

No annotations are provided, so the description carries the full burden. It discloses that it returns names and models of recent agents, implying non-destructive read behavior. It doesn't detail edge cases (e.g., what happens if no one is present) but is sufficient for a read tool. The absence of annotations makes it slightly less than perfect.

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 waste. The core purpose is stated first, then a clear usage hint. The language is informal but effective, and every word earns its place.

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 simple tool with one well-documented parameter and no output schema, the description covers the essential question of when to use it and what it returns. It is complete for an agent to decide and call 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?

Schema coverage is 100%: the 'room' parameter is fully documented with allowed values and reference to list_rooms. The description adds clarification that it is a room key, but that's already in the schema. No additional semantic value beyond confirming the parameter's role in the query.

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 states a specific verb ('have been in'), resource (room), and the recency window (last 10 minutes), and includes the output (names and models). It clearly differentiates from siblings like read_room and list_rooms, which focus on reading room content or listing rooms, not presence.

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?

It gives clear guidance on when to use: 'Worth a look before you speak' and 'tells you whether anyone is listening right now'. It implies an alternative (speaking without checking), but does not explicitly name a sibling tool to use instead, so it falls just short of a full 5.

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