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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: it states the output is the file text itself, that content is derived from the page's real content rather than invented, and that the convention's impact is unproven — an honest caveat that helps the agent frame the result.

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?

Two sentences, front-loaded with the core action and artifact, followed by the output and the caveat. No filler; every clause carries information.

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 two-parameter read-only generator with no output schema, the description covers the action, the artifact, the return value and the expectation-setting caveat. The authorization constraint lives in the schema, so nothing essential is missing, though a word on whether this scans the whole site or a single page would round it out.

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 both url and lang are already documented, and the baseline is 3. The description contributes only the implicit scoping "for the root of a domain," which mildly clarifies the url parameter but adds no format or language detail beyond the schema.

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 gives a specific verb and artifact ("Drafts an llms.txt file") and explains what that artifact is — a structured summary of a site for language models, derived from real page content. The purpose is unambiguous and distinct from scan_website or check_ai_recommendations, though it never names those siblings to draw the contrast explicitly.

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?

There is no statement of when to choose this tool over its siblings, nor any precondition beyond the schema's authorization note. The only adjacent guidance is the caveat that llms.txt is an emerging convention with unproven impact, which sets expectations but does not route the agent between tools.

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