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

Annotations only declare readOnlyHint and openWorldHint, but the description adds material context beyond them: a $0.002 USDC per-successful-call x402 payment model across Base, Solana and Arc, the fact that failed calls are not charged, the 20-result cap, and the exclusion of units/reference ranges. It still does not disclose matching semantics (exact vs substring) or rate limits.

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?

The resource and operation are front-loaded before the payment details, and every clause carries information (scope, output shape, limits, pricing). It is dense but slightly long in a single sentence, though nothing is genuinely expendable given the pay-per-call model.

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 100% schema coverage and an output schema, the description needn't explain return values, and it still summarizes them (codes, names, total count). Payment terms and exclusions are covered; the only gap is how term matching behaves, which an agent may want before spending $0.002 per call.

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 both parameters are fully documented in the schema (max 1–20 default 10, term 2–60 characters). The description adds only the 'up to 20 per call' ceiling, which the schema already conveys, so the 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?

The description names the specific resource (LOINC laboratory and clinical test codes via NLM Clinical Tables) and the specific operation (match a term, return LOINC number and long common name plus total match count). No sibling tool covers LOINC, so the resource alone disambiguates it from ICD-10, CPT, or RxNorm siblings.

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 implied: search LOINC names with a term, up to 20 results per call, and the definition warns that units and reference ranges are not included, which signals when to look elsewhere. However, it never states when to prefer this over a sibling terminology tool or what kind of term input works best.

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