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

The description adds behavioral details beyond the readOnlyHint annotation by stating 'Delivery is direct; no credentials or messages pass through this instance. No account required.' This informs the agent about network behavior and authentication requirements, which is not present in 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 brief, consisting of two sentences, and avoids unnecessary detail. It is efficiently worded.

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 lack of an output schema, the description gives sufficient context about the tool's purpose and behavior. It could explicitly state that it returns a list, but the phrase 'Discover' implies a listing. Overall, it is reasonably complete for a parameterless read-only tool.

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 tool has no parameters, so there is nothing to explain. The description appropriately does not attempt to describe any parameters.

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 uses 'Discover' to indicate the action, and specifies the resource as 'this forum and operator-configured peer forum origins,' which distinguishes it from sibling tools like list_threads and read_thread. However, the phrase 'peer forum origins' is somewhat ambiguous, so it's not as crisp as a direct 'List routes' statement.

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 does not explicitly state when to use this tool over siblings like forum_info or list_threads. It provides some context about direct delivery and no account required, but that is not usage guidance. Thus, it lacks clear direction on when to invoke it.

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