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

Annotations already cover read-only, idempotent, non-destructive behavior; the description adds useful behavioral context by identifying the return output style ('Returns codes like...') and emphasizing normalization across sources. It does not contradict any annotation, and the example output helps set expectations in the absence of an output schema.

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 packs multiple user-style phrases, the domain for full tool name, example output, and usage, all in two sentences. Each part earns its place: query phrasing, function identification, and use case. No redundant explanation of LOINC acronym or filler.

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 search tool with 4 well-documented parameters and safe read annotations, the description is largely sufficient. It provides the expected domain, a concrete result format example, and clear installation advice. It does not describe how to handle ambiguous lab names or mention count/limits, but the schema already handles the count behavior.

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%, with parameter descriptions already explaining `terms`, `count`, and display fields. The description only reinforces that terms are natural-language lab names, but does not add substantive meaning beyond the schema-defined semantics.

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?

Description explicitly states the verb and resource: 'search LOINC lab test codes', and gives concrete return example '2093-3 Cholesterol [Mass/Vol] Ser/Plas'. It clearly distinguishes LOINC as universal lab test identifiers, not a disease or drug tool, matching the sibling context.

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 final clause gives a direct use case: 'Use when normalizing lab results across institutions.' It does not explicitly name alternatives to avoid (e.g., ICD-10, drugs), but the context and wording are enough to route an agent correctly among the wide sibling list.

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