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

Annotations already declare the full safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add coverage context — which it does by naming the exact seven retailers and qualifying retailer status as 'where tracked', signaling partial data. It stops short of describing behavior for unknown or unmatched ingredient names and gives no sense of payload shape, which keeps it below a 5.

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 resource definition, then the usage cue; two sentences with no filler. The long enumeration of returned facets is dense but earns its place because no output schema exists to carry that information.

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 lookup with no output schema, the description does the heavy lifting by enumerating what comes back and flagging data-coverage limits ('where tracked'). The remaining gap is no-match / unknown-ingredient behavior, which matters for a name-keyed lookup, preventing a 5.

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 single parameter already carries an example-bearing description ('monk fruit extract', 'astaxanthin', 'inulin'). The prose adds no naming conventions, synonym handling, or normalization guidance beyond what the schema supplies, so baseline 3 applies.

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 — 'Sourcing and regulatory profile of one food, beverage or supplement ingredient' — and enumerates the concrete contents (supplier counts and countries, certification shares, forms/specs, GRAS notices, 7 named retailer statuses). This composite scope implicitly distinguishes it from narrower siblings like find_ingredient_suppliers or search_gras_notices, so an agent knows it is the consolidated view rather than a single-facet lookup.

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?

'Use it to compare ingredient options or check supply depth and regulatory position before choosing an ingredient' gives a clear decision context. It does not name alternatives or state when to prefer find_ingredient_suppliers / search_gras_notices instead, so the routing guidance stops short of explicit exclusions.

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