list_known_devices

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It states the tool lists devices discovered during the session, but does not explicitly confirm it is read-only, non-destructive, or free of side effects. While 'List' implies a safe read, the description adds no contextual details about return behavior, caching, or prerequisites.

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 a single, clear sentence that front-loads the purpose without extraneous words. Every word contributes to the definition, achieving maximum conciseness.

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 low complexity (zero parameters, no output schema), the description adequately covers the core functionality. It specifies the session scope, which is the key contextual detail. It could optionally mention that this is a read-only list (since annotations are absent), but given the simplicity, the description is nearly complete.

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 zero parameters and schema coverage is trivially 100%. Per the rubric, the baseline is 3 when schema coverage is high, and the description adds no parameter information because none is needed. This is appropriate for a parameterless tool.

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 is specific: 'List devices discovered during this MCP server session.' It names the verb ('List'), the resource ('devices'), and the scope (session-discovered). This clearly distinguishes it from siblings like 'discover_devices' (initiates discovery) and 'get_device_state' (retrieves state).

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 a clear context (session-scoped devices) but does not explicitly state when to use this tool versus alternatives like 'discover_devices' or 'list_pairings'. It implies the tool is for viewing already-discovered devices, but there is no direct guidance on exclusions or alternative recommendations.

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