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 value beyond that by disclosing what comes back (a canonical URL plus a link to full documentation) and what is out of scope (caller URLs), which matters because there is no output schema.

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 short sentences, no filler, with the core action and the search-derived id requirement front-loaded before the scope exclusion. Every clause carries information an agent would otherwise have to guess.

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 single-parameter read tool with rich annotations, the description covers purpose, precondition, return shape and scope limits. The only minor gap is that the format of the 'link to full documentation' field is not hinted at, which is acceptable given the simplicity of the tool.

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 description coverage is 100% and the schema's own example ('doc:pricing') already shows the id format. The description adds only the provenance rule (an id returned by search), which is useful but marginal; 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 and resource: fetch the first-party catalog summary for an id. It explicitly ties itself to the sibling 'search' as the source of the id and narrows scope with 'does not retrieve caller URLs', so an agent can tell it apart from search and from any caller-URL tool.

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?

Gives a clear precondition for use: the id must have come from search, which effectively sequences the two tools. It also carves out an exclusion ('does not retrieve caller URLs'), but it does not name an alternative tool for that case or state when to prefer another sibling.

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