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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real context beyond that: that access is public/free (no cost), that querying leaks no message text, and that the head hash seal only appears once the room is closed.

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?

One tight, front-loaded sentence that lists the return contents first and the negative constraint second. Every clause carries information; nothing is padded.

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?

With no output schema, the description usefully enumerates the returned fields and clarifies the seal/closure condition. Only minor gaps remain, such as whether the head hash is always present for open rooms or any rate-limit behavior.

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?

There is a single required parameter fully documented in the schema ('rm_... ID'), giving 100% coverage, so the baseline is 3. The description adds no further meaning about the ID format or lookup behavior beyond the schema.

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?

States the resource (a room) and enumerates exactly what is returned: parties, price, message count, head hash, and its seal once closed. It implicitly carves out its sibling room_transcript via 'No message text', so an agent can differentiate, though no sibling is named explicitly.

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 message text' implies that message-reading belongs to room_transcript, which is useful routing. However there is no explicit when-to-use guidance versus room_list, room_verify, or the fortress/gateway info tools, so the agent must infer scope.

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