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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context beyond annotations: it specifies the output types (standardized drug concepts, RxCUI, term types, synonyms), describes the source authority (RxNorm as the US standard), and notes the filter behavior. This enriches the agent's understanding without contradicting the annotations.

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 four sentences with no fluff. It front-loads the action, then covers output, domain context, downstream usage, and filtering—all in logical order. Every sentence contributes useful information, making it both compact and information-dense.

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 read-only search tool with an output schema and annotations covering safety, the description is complete. It explains what to search by, what results contain, how to continue the workflow, and how to filter. The limit parameter and output structure are covered by the schema and output schema, so nothing needed to select and invoke the tool correctly is missing.

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?

The schema has 100% description coverage, so the baseline is 3. The description adds extra semantics by clarifying the name parameter accepts generic, brand, or ingredient names, and by giving real-world meanings for the tty enum values (IN, BN, SCD/SBD) that are not fully explained in the schema. This practical guidance helps the agent choose values appropriately.

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 states a specific verb ('Search'), the exact resource ('NIH RxNorm drug database'), and the supported search inputs (generic name, brand name, ingredient). It enumerates the return fields (RxCUI identifiers, term types, synonyms), making the tool's function unmistakable and distinguishing it from the listed sibling tools like rxnorm.drugs.properties and rxnorm.drugs.class.

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 explicitly tells the agent to use the RxCUI from results with rxnorm.drugs.properties and rxnorm.drugs.class for deeper information, positioning this tool as the search entry point. It also provides filter guidance via term type (tty) with concrete examples (IN, BN, SCD/SBD). However, it does not state explicit exclusions or when not to use this tool in favor of an alternative, though the downstream guidance implies the workflow.

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