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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it specifies that no genotype input is needed and characterizes the returned evidence provenance (CPIC/DPWG guideline, drug label, or primary literature).

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 core behavior is front-loaded in the opening sentence, followed by two short, purposeful sentences. The first sentence is dense but every clause carries information; minor tightening only.

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 no output schema, the description correctly takes on the burden of describing returns (covered vs. uncovered drugs, associated genes, evidence basis) and notes the input requirement. It omits the list-size limit and any note on partial/unmatched names, so it is strong but not exhaustive.

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% and the single parameter is already documented with an example; the description's phrase 'list of generic drug names' restates the schema rather than adding format or constraint detail (e.g., the 30-item maximum). Baseline 3 is appropriate when the schema carries the parameter 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?

States a specific verb (screen/say which) and resource (a list of generic drug names), and enumerates exactly what it returns: which drugs have a curated drug–gene record, which genes, and the evidence type. The batch-of-generic-names framing implicitly distinguishes it from the singular lookup_drug_gene sibling.

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?

Gives a clear when-to-use statement ('Use it before discussing whether genetics could matter for someone's medicines') and a precondition ('Needs no genotype'). It does not explicitly name a sibling alternative (e.g., lookup_drug_gene for single-drug detail) or state when not to use it, so it stops short of full routing guidance.

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