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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so safety is covered. The description adds genuinely useful behavioral context beyond that: it returns history and verdicts, and it explicitly distinguishes 'never seen' from 'seen but failed' — an output-semantics nuance 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?

Three front-loaded sentences: the core action first, then the usage framing, then the important caveat about the two failure modes. Efficient overall, though the middle framing sentence is close to redundant with the opening sentence.

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 carries the burden of explaining returns and does so (history and verdicts), and annotations cover the safety profile. It is nearly complete for a read-only resolution tool, with the remaining gap being no guidance on how the four optional identifier parameters combine.

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 50% (uid and upi are documented; gtin and serial are not). The description maps some meaning onto them by framing 'a GTIN plus serial' as a composite alternative and 'GS1 Digital Link URI' as the upi form, but it never clarifies precedence or whether these forms are mutually exclusive. This partially compensates for the coverage gap.

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 (resolve), the resource (a unit), and enumerates the accepted input forms (chip UID, GS1 Digital Link URI, GTIN+serial) plus the return content (history and verdicts). The distinction between a non-resolving identifier and a failed verification effectively separates it from verify_chip/trace_unit.

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?

'This is the tool for "what is this thing in front of me"' gives a clear situational context for use, and the failure-mode guidance tells the agent how to interpret outcomes. However, no sibling is named as an alternative, so there is no explicit when-not guidance against verify_chip or trace_unit.

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