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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint as true, and destructiveHint as false. The description adds behavioral detail beyond annotations: 'Fetches the page, extracts title/description/key links, and emits the standard llms.txt markdown format.' It does not contradict annotations and provides clarity on the fetch-and-generate process.

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 three sentences long, front-loaded with the main purpose, and every sentence adds value. No redundant or filler content. It is efficient and easy to parse.

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?

Given the tool's simplicity (2 parameters, no output schema, no nested objects), the description provides all necessary context: input (URL), behavior (fetch & extract), output format ('standard llms.txt markdown format', 'single text blob ready to drop at site-root/llms.txt'), and use cases. Nothing missing.

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 coverage is 100% for both parameters. The description adds value by providing examples for 'url' ('e.g. "https://example.com" or a specific landing page') and default/max values for 'max_links' ('default 25, max 50'). This goes beyond the schema's basic descriptions.

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 states the verb 'generate' and the resource 'llms.txt file', with explicit scope 'for any URL'. It distinctively explains what it does: 'Fetches the page, extracts title/description/key links, and emits the standard llms.txt markdown format'. No sibling tool performs the same function, so it is well-differentiated.

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 lists concrete 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.' It provides when to use but does not explicitly exclude scenarios or compare to alternatives, though no obvious alternatives exist among siblings.

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