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

With no annotations, the description carries full burden. It reveals that the tool returns total unread count and per-room breakdown, and limits to subscribed/member rooms. However, it does not disclose behavior like idempotency (implied by GET), error handling, or any side effects. It provides moderate transparency.

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 is extremely concise, using just two sentences (plus a title line) to convey purpose, return value, and scope. Every part is necessary and front-loaded. No wasted words.

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 (1 param, no output schema), the description adequately explains what is returned (total and per-room unread counts) and the scope. It does not cover error scenarios or response format details, but for a straightforward read tool, it is nearly complete. Missing only minor details.

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% for the single parameter 'limit'. The description does not add additional meaning or context for the parameter beyond what the schema provides. Baseline 3 is appropriate as the schema already documents the parameter adequately.

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 retrieves unread counts, providing total and per-room breakdown. It also specifies the scope (rooms the user is subscribed to or a member of). While it doesn't explicitly differentiate from siblings like rooms_inbox, the purpose is specific and distinct enough.

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?

No guidance is given on when to use this tool versus alternatives such as rooms_inbox or rooms_summaries. The description only includes a constraint (which rooms are included) but does not help the agent decide between similar tools.

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