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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses authentication requirements ('user-auth mode, active session'), permission prerequisites ('read access: ownership or room membership'), and enumerates the relevant error cases (400, 401, 403, 404). This is substantial behavioral context that the annotations do not provide, and 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?

The description is compact and front-loaded: the core action and return values appear first, followed by tightly packed auth and error information. Every clause earns its place with no repetition or filler.

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 tool with one optional parameter and no output schema, the description is nearly complete: it covers return payload fields, default parameter behavior, auth requirements, and failure modes. The only material gap is the lack of explicit guidance distinguishing this tool from the similarly named ethora-app-get-default-rooms sibling, leaving the agent to infer the difference from the name.

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 schema already fully describes appId, including that it is optional and defaults to the app most recently passed to ethora-app-select. The description only paraphrases this behavior and adds no new parameter format or usage semantics beyond the schema, so the 100% schema coverage baseline of 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 states a specific verb and resource: 'List the default chat rooms of a specific Ethora app,' and it specifies the returned fields (JIDs and titles). However, it never references the near-identical sibling ethora-app-get-default-rooms, so differentiation must be inferred from the tool name rather than the description.

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 gives clear invocation context: appId is optional and defaults to the currently selected app, and it states the required auth mode and read-access conditions. It does not explicitly explain when to choose this tool over ethora-app-get-default-rooms or other listing siblings, so alternatives are not named.

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