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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, and the description's 'server marks it read-only, so it runs straight away' largely restates that. It does add useful disclosure that the response includes generated Markdown content, which is beyond the annotations, but nothing about size, freshness, or failure modes when llms.txt is disabled.

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 return-value sentence is front-loaded and earns its place. The parenthetical ability ID and the 'Through Royally...' sentence are meta-commentary of marginal value, but they are short and do not bury the essential 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?

With no output schema, the description steps up by naming the three returned fields (enabled status, URL, Markdown content). Combined with full schema coverage on the single site_id parameter and rich read-only annotations, an agent has enough to invoke it correctly; only the behavior when the file is disabled is unspecified.

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?

Only one parameter (site_id) exists and schema description coverage is 100%, with the enum value and site URL documented in the schema. The description adds nothing about the parameter, but with full schema coverage the baseline of 3 applies.

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 names a specific resource (llms.txt) and enumerates exactly what is returned: the enabled flag, the URL, and the generated Markdown content. It is clearly distinguishable from nearby siblings like get_robots_txt or get_sitemap_status by resource, though it does not explicitly contrast itself with them.

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 guidance on when to call this versus alternatives such as rank_math_get_robots_txt or get_settings. The only hint is that it is a read that 'runs straight away,' which is behavioral, not usage-oriented. An agent must infer the intent from the resource name alone.

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