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

Annotations only declare the safety profile (readOnly, idempotent, closed-world), so the description adds substantial non-redundant context: supplements return different fields (supplement, what_studies_looked_at, studied_amounts, ceiling, cautions, source) instead of rda/upper_limit, the NIH fact sheet is linked, and country=GB changes both the amounts shown and the shop link site. That is exactly the behavioral detail the annotations cannot convey.

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?

Front-loaded with the core purpose and example queries before the long enumerations, so the key information is reachable immediately. The extensive nutrient and supplement lists are somewhat repetitive — "vitamin, mineral" already implies the enumerated vitamins — but they plausibly earn their place for matching free-text name inputs.

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?

With no output schema, the description correctly compensates by describing the returned fields, the conditional nutrient-vs-supplement shape, and country-specific behavior; annotations cover safety. The only notable omission is any statement of how this differs from the sibling get_supplement.

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 goes beyond it by explaining that country=GB yields UK/NHS amounts surfaced in a uk field and also selects the shop link site. It also confirms name accepts both straight nutrients and common forms (e.g., magnesium glycinate).

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 precisely: it returns what a vitamin, mineral or supplement does, adult requirements, limits, cautions and food sources. An agent can tell what it retrieves without opening the schema. It does not, however, differentiate itself from the sibling get_supplement, which looks like it overlaps heavily with the supplement half of this 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?

Usage is anchored by concrete trigger phrasings ("what does magnesium glycinate do?", "how much vitamin D do I need?", "is ashwagandha safe?") that make the intended question type obvious. It also clarifies the nutrient-vs-supplement split in outputs. It stops short of naming when to choose check_dose or get_supplement instead.

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