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

Even with readOnlyHint=true, the description adds rich behavioral context: list ordering (newest first), response fields (title, description, written date, address), markdown body for full guides, and the fact that unpublished guides are not found. These go well beyond the annotation and fully describe the operation's observable behavior.

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?

Four short, front-loaded sentences carry all necessary information without repetition. The description opens with the resource, then clearly separates the no-slug and with-slug cases, and closes with the access constraint. Every sentence earns its place.

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 read-only tool with no output schema and three optional parameters, the description covers the list and detail modes, filtering behavior, returned fields, format, and the unpublished-not-found rule. Nothing an agent needs to invoke 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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaning for q by specifying that it matches 'every word' across title, description, or slug, and for slug by explaining it returns the full guide as markdown. This is more than the schema alone provides, though limit semantics are already fully documented in the schema.

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 resource ('the published guides') and verbs: listing with no slug, reading in full with a slug, filtering via q. It clearly distinguishes its two modes and the behavior of each, making it easy to tell this tool apart from siblings like product or search_catalogue without opening the schema.

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 gives clear operational guidance: use without slug to get the list, use with slug to read a guide in full, and use q to filter. However, it does not name alternatives or state when not to use this tool versus a sibling, so it stops short of explicit exclusions.

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