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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description adds value beyond them: the return shape ('llms.txt content and output metrics'), the authentication requirement (Bearer token), and the cost model ('billing is per input character'). No contradiction exists — generating derived content from inputs is a non-mutating, idempotent operation consistent with 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?

Three sentences with no waste: sentence one states the core function, sentence two packs return value, auth, and billing, sentence three routes the compliance use case to a sibling. The main purpose is front-loaded and every sentence 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?

For a tool with 100% schema coverage, rich annotations, and no output schema, the description covers the operational essentials: purpose, return value, auth, cost, and sibling routing. The minor gaps — specifics of 'output metrics' and error conditions — do not prevent a correct first call.

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?

Schema description coverage is 100%, so each parameter (name, endpoints, links, pricing, tagline, overview) is already documented in the schema. The description's listing of metadata categories adds framing but no new parameter-level meaning, and it omits tagline. The baseline 3 applies when the schema carries the full burden.

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 opening statement specifies a concrete verb and resource: 'Generate an llms.txt agent-discovery file from structured service metadata (name, endpoints, overview, links, pricing).' It names the input categories and the artifact produced, and it distinguishes the tool from sibling `validate` by naming that alternative explicitly. An agent can tell what this does without opening the schema.

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 provides clear when-to-use context (create an llms.txt from structured metadata) and one explicit exclusion: 'To check an existing llms.txt for spec compliance, use `validate`.' However, it does not address the other five siblings (convert, diff, estimate, patch, prune), so the agent must infer those boundaries from the tool name alone.

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