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

Annotations already convey readOnly, idempotent, and non-destructive behavior. The description adds valuable context by detailing the internal steps: 'Fetches the page, extracts title/description/key links, and emits the standard llms.txt markdown format.' It also clarifies the output is 'a single text blob ready to drop at site-root/llms.txt,' making the tool's behavior transparent beyond 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?

The description is four sentences that efficiently front-load the main action and process. The 'Useful for' list adds practical value without fluff. Minor redundancy exists in describing output twice ('standard llms.txt markdown format' and 'single text blob'), but overall it is well-structured and concise.

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 description compensates by explaining the output format and destination. Combined with full parameter schema coverage, helpful annotations, and clear use cases, the description provides enough context for correct invocation. It does not cover edge cases like network failures, but these are less critical for a read-only, idempotent tool.

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 input schema covers both parameters fully: url as 'Full URL of the site to summarize' and max_links with default/max. The description hints at 'key links' which aligns with max_links, but it does not add meaningfully beyond the schema. With 100% schema coverage, the baseline of 3 is appropriate.

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 uses a specific verb and resource: 'Generate a production-ready llms.txt file for any URL.' It clearly distinguishes itself from siblings by focusing on generating the llms.txt file itself, not just scanning or researching. The mention of 'standard llms.txt markdown format' and site-root placement makes the purpose unambiguous.

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 use cases: 'getting a client's site indexed by AI, drafting llms.txt for your own project, or auditing how an AI crawler would see a competitor.' However, it does not explicitly name alternative tools or state when not to use this tool, falling 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.