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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine interpretive context beyond annotations: what fields come back (GRN number, basis, notifier, filing/closure dates, FDA response letter) and two critical caveats — absence of a notice does not mean non-GRAS due to self-affirmed GRAS, and a notice covers only its stated uses. Those caveats are the kind of context annotations cannot carry.

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?

Three sentences, front-loaded with what the tool searches and followed by return fields then caveats — a logical order with no filler. Slightly dense in the middle sentence, but every clause 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?

With no output schema, the description correctly enumerates the returned fields so the agent knows what to expect. Combined with the coverage caveats, an agent has enough to call the tool and interpret results; only the pagination/limit behavior is unaddressed, which is a modest omission for a simple 3-parameter search 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 coverage is only 33%, and the description partially compensates by naming the three searchable facets (substance, intended use, notifier) that map to the 'field' enum. However, it says nothing about the 'limit' parameter, its default of 10, or the 25 maximum, and adds no format guidance for 'query' beyond what the schema already documents. Baseline 3 is appropriate given partial schema coverage.

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 (Search) plus the exact resource (FDA GRAS Notice inventory) and names the searchable facets: substance, intended use, notifier. This is clearly distinct from every sibling tool (nutrition labels, retailer ingredients, RACC categories, label ingredients, sweetener replacement), so an agent can route to it 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?

Gives a concrete use case — checking whether a food ingredient has a GRAS notice before formulating for the US market — which tells the agent when this tool applies. It does not explicitly name an alternative or a when-not-to-use rule, but the domain is narrow enough that no sibling overlaps, so the absence of exclusions is a minor gap.

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