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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered in structured data. The description adds meaningful behavior by enumerating what the response contains, which matters because no output schema exists; it does not mention failure modes (e.g., unknown slug) or caching, keeping it below top marks.

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?

A single dense sentence with the scope, the key, and the return contents front-loaded; no filler or redundant restatement of the title.

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 one-parameter read-only lookup this is fully sufficient: the key's origin is explained, the returned fields are listed in lieu of an output schema, and annotations cover the safety profile. An agent can call it correctly with nothing else.

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% and the schema itself supplies an example value ('noon-line'), so the schema carries the parameter documentation. The description contributes only the provenance hint that the slug comes from search_rugs; baseline 3 applies when the schema does the heavy lifting.

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 ('Full details'), a single resource ('one rug'), and an explicit retrieval key ('by its slug'), then enumerates the exact fields returned (description, size, colours, materials, knot density, lead time, image, page). This makes it immediately distinguishable from the list/search siblings search_rugs and list_collections.

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 parenthetical '(from search_rugs)' tells the agent where the required slug comes from, establishing the intended workflow: search first, then fetch details. There are no explicit when-not conditions or named alternatives beyond that hint, so it stops short of full routing guidance.

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