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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the safety profile is fully covered. The description adds the returned field list and the RxCUI prerequisite, which is useful but not a substantial behavioral disclosure beyond what annotations and the output schema already 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?

The description is compact and front-loads the core action and return fields. The sentence about RxCUI being used in medication reconciliation adds context but is slightly more than strictly necessary. Overall it remains efficient and readable.

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 a single documented parameter, rich schema coverage, an output schema, and annotations covering mutability, the definition is nearly complete. It includes the search prerequisite and usage domain, but does not address error scenarios or how this differs from rxnorm.drugs.class/ndc_lookup. Still, an agent can invoke this correctly from the provided information.

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 schema already documents rxcui with type, minLength, examples ('1191' for aspirin), and a source instruction. The description reinforces the value of the parameter but does not add new semantic meaning beyond the schema. One minor inconsistency exists: the schema references 'rxnorm.drug_search' while the description correctly says 'rxnorm.drugs.search'.

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 opens with a specific verb and resource: 'Retrieve detailed RxNorm properties for a drug concept identified by its RxCUI.' It further defines the exact fields returned (canonical name, synonym, TTY, language, suppression status), which clearly distinguishes this from siblings like rxnorm.drugs.search and rxnorm.drugs.ndc_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?

The description gives concrete context for when this tool is relevant — medication reconciliation, clinical decision support, and insurance formularies — and explicitly instructs the agent to obtain the RxCUI via rxnorm.drugs.search first. It stops short of contrasting against all related siblings (e.g., rxnorm.drugs.class), so it is clear but not fully exhaustive.

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