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

readOnlyHint=true already tells the agent this is a safe read, so the annotation carries the safety profile. The description adds only the underlying REST route (GET /rxcui/{rxcui}/ndcs), and says nothing about rate limits, whether historical/obsolete NDCs are included, or what the response contains. Little value beyond the structured fields.

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?

Two short sentences, front-loaded with the purpose. The REST endpoint mapping is secondary but plausibly useful for an agent correlating with RxNav docs; there is no padding or repetition.

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 annotations and no output schema, the definition is minimally sufficient, but it omits the return shape (e.g., NDC status, 9/10-digit codes) and any note about historical versus current NDCs, which an agent selecting this tool would benefit from knowing.

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?

There is a single parameter (rxcui) documented at 100% schema coverage, so the schema already carries its meaning. The description adds no format, sourcing, or validity guidance beyond what the schema provides, making the baseline 3 appropriate.

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 and resource ('Get the NDCs associated with a concept') and names the exact resource type (NDCs), which distinguishes it from siblings like rxnorm_get_drug_classes or rxnorm_get_related_by_type. It does not explicitly contrast with siblings, but the resource specificity makes the distinction clear.

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 when-to-use guidance, no prerequisites (e.g., you must already have an RxCUI), and no mention of alternatives such as finding a concept first via rxnorm_find_rxcui_by_name. The agent is left to infer usage from the purpose alone.

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