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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real context beyond them: the exact count and themes of the guides and the fact that some are online without registration while others arrive as PDFs by e-mail, which shapes how the agent should present the result.

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?

Two sentences, no filler, with the enumeration of contents front-loaded and the usage note placed last. The first sentence is dense but every clause (URL, format, signup page) conveys distinct 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?

There is no output schema, yet the description compensates by describing the shape of each returned entry: URL, delivery format, and signup page. For a zero-parameter read tool with full annotation coverage, nothing an agent needs in order to call and present it correctly is 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?

The tool takes no parameters, so there is nothing to disambiguate and the baseline of 4 applies. The description correctly does not invent input options.

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 (list) and resource (the 6 free gluten-free guides), enumerates their subjects, and details what each entry carries (URL, format, signup page). It is clearly distinguishable from list_comparatifs and search_articles, though it never explicitly names the potentially confusable sibling get_store_guide.

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 closing sentence gives explicit when-to-use guidance: offer it to a user who is starting out or wants a printable list. That is clear context, but no alternative tool or exclusion condition is named, so it falls short of a full when/when-not statement.

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