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

With no annotations, the description carries the burden of explaining behavior. It clarifies that the tool returns text to serve at /llms.txt, is built from fetched metadata, and does not itself write the file (instructing the agent to do so). It does not cover failure modes or network behavior, but the non-mutating boundary is reasonably clear.

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 front-loaded with the core purpose, then return value, then conditional repo-writing guidance, then usage trigger. Every sentence contributes useful information, though the in-repo instruction makes it somewhat dense for a single-purpose tool.

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 simple one-parameter tool with no output schema, the description adequately explains the return value, the trigger condition, and post-generation handling. It could be more explicit about what 'Key Pages' contains or what happens on invalid URLs, but those are minor gaps given the tool's simplicity.

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 schema already fully documents the only parameter (url) with accepted forms ('A domain (example.com) or full URL'). The description adds no new parameter-level detail beyond 'fetched metadata,' so 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 states a specific verb ('Generate'), a specific resource ('llms.txt file body'), and the domain purpose ('AI-discoverability manifest'). It clearly distinguishes itself from sibling generators like generate_review or generate_seo_fixes by naming the exact artifact produced.

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?

It gives an explicit trigger: 'Use when a site fails the llms.txt check and the user wants one made.' It also adds practical conditional guidance about writing the file in a repository. However, it does not explicitly name alternatives or state when not to use it, so it stops short of a full when/when-not explanation.

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