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

Annotations already declare readOnly, idempotent and closed-world behavior, so the safety profile needs no restating. The description adds useful scope information by naming the record's components, including recalls, but omits behavioral details such as what happens for an unknown id and that a point-in-time view up to a year back is possible.

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 tight sentence with the resource and the key upfront and the returned fields listed after the colon, so nothing is wasted. It is a sentence fragment rather than a complete explanatory statement, which slightly limits readability for an autonomous agent.

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?

Two simple parameters and no output schema mean the enumerated return fields do real work here. Still, an agent gets no information about not-found behavior or the historical as_of dimension, and there is no output schema to fall back on for the response shape beyond the field list.

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 id parameter's format (pw_d_…) is fully documented in the schema, so the baseline applies. The description earns a small amount of extra credit by framing the id as the lookup key and hinting at the breadth of the returned record, though it adds nothing about the optional as_of parameter beyond 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?

States a specific resource retrieved by a specific identifier ('the full record for a Pillwise drug id') and enumerates the contents (names, ingredients, form, strength, packages, recalls). It is clearly distinct from list/search siblings, though it does not explicitly contrast itself with the other identifier-based lookups (lookup_ndc, lookup_rxcui).

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 prerequisite is implied by 'for a Pillwise drug id', so an agent can infer this is the follow-up call once it holds a pw_d_ id. However, there is no explicit when-to-use statement, no mention of when to prefer lookup_ndc/lookup_rxcui/search_medications, and no guidance on using the historical as_of variant.

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