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

Annotations already declare readOnly=true, idempotent=true, destructive=false, closed-world, so the safety profile is covered. The description adds only that resolution happens against a 'CPG Knowledge Graph door' and that success implies the product is real; it says nothing about failure behavior, missing GTINs, or lookup scope.

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 front-loaded sentence that states the verb, resource and purpose with no filler. The slightly colloquial 'Knowledge Graph door' is the only soft spot in an otherwise tight formulation.

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 read tool with an output schema and full annotation coverage, the description supplies what an agent needs to select and call it. Only the absence of failure-case context (what an unresolved GTIN means) keeps it from being fully complete.

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 0%, so the description must carry the parameter burden. It does expand the acronym to 'Global Trade Item Number' and identifies it as a product identifier, which adds real meaning, but it supplies no format guidance (digit count, checksum, accepted variants).

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?

The description gives a specific verb and resource ('resolve a Global Trade Item Number') plus an outcome ('Confirm the product is real'), which is clearer than a bare restatement of the name. It does not, however, explicitly differentiate itself from the other resolve_* siblings (resolve_actor, resolve_jurisdiction), leaving the agent to infer the distinction from the resource noun.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites (e.g. where a GTIN comes from), and no exclusions. The phrase 'Confirm the product is real' implies a validation use case, but that is inference rather than guidance.

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