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

With no annotations, the description carries the full disclosure burden and does real work: it states the €0.01-per-site charge, that billing hits the Bearer API key, and that robots.txt is respected. Pagination/rate limits, timeout behavior, and failure modes when a site blocks crawling are not covered, so the picture is good but incomplete.

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?

Front-loaded with the core behavior, then cost/auth, then parameters — a sensible order with no filler. The parameter clause is crammed into one semicolon-chained sentence, which costs a little readability.

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?

An output schema exists, so return values need not be described, and the cost, auth, and crawl-limit context is supplied. The one real omission is that url is functionally mandatory even though the schema marks nothing required, which an invoking agent needs to know.

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 0%, so the description must compensate and it partly does: url is the site url, max_pages is 1–20 pages crawled only when no llms.txt exists, default 20. Gaps remain — the schema types max_pages as a string with a null default while the description says numeric 1–20 with default 20, and nothing explains whether url must include a scheme or is effectively required despite 0 required 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?

States a specific verb set and resource: returns an existing /llms.txt or builds one from the sitemap, per the llmstxt.org spec. That distinguishes it cleanly from siblings such as seo_audit, url_to_markdown, and readability_score, which also touch site content but do not produce this artifact.

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 fetch-or-generate logic is explicit (use the existing file when present, otherwise crawl the sitemap, otherwise fall back to homepage links), which tells the agent what it will get. It stops short of naming an alternative tool or stating when not to use it, so it lands just below the top band.

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