federation_discover

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

Beyond the `readOnlyHint=true` annotation, the description explicitly says 'Read-only — never parses an entry into a connectable spec and never ratifies anything.' It also adds root-resolution behavior via the environment variable. This is materially useful behavioral context beyond the annotations alone.

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 concise and front-loaded with the core operation, then adds essential constraints. The final quoted sentence is slightly rhetorical, but all other content earns its place.

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 return value is only implicitly described, and the required `app_id` remains unexplained. The root semantics and non-mutating behavior are well covered, but this is not quite complete for confident invocation.

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 `root` parameter is well documented: it is a filesystem path with a clear default (home directory, fallback to `$WILLOW_MCP_FEDERATION_SCAN_ROOT`). However, `app_id` is required and has zero schema coverage nor any mention in the description, so an agent has no information about what value to supply.

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 specifies the operation: scan `.mcp.json` files under `root` that the ratified registry does not yet own, and frames it as a 'Shadow-IT scan'. It also names the question answered — 'Which MCP servers exist that willow-mcp does not know about' — which distinguishes it from known-server lookups like `federation_list_servers`.

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 contextual guidance: it is the first question an orchestrator must answer before federating. It does not explicitly name alternatives or state when not to use the tool, so it falls just short of a 5.

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