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

Annotations already declare readOnly/openWorld/idempotent behavior, and the description adds scope context (curated PGx database, CC BY-SA source). However, most listed return fields are also available in the output schema, so the incremental behavioral disclosure beyond annotations is modest.

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?

Three sentences with no wasted words: action/resource, return highlights, and scope/license. The action is front-loaded, and every sentence earns its place.

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-only lookup with an output schema, the description provides adequate context: what it searches, what it returns, and coverage/license. It leaves out edge-case matching behavior, but that is minor given the schema richness.

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 single required parameter is fully documented in the schema (100% coverage), including examples. The description's repetition of examples and database scope adds no new semantic meaning for the 'name' parameter beyond what the schema already provides.

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 ('Search'), names the exact resource ('PharmGKB curated drug/chemical database'), and gives concrete examples (warfarin, clopidogrel). The drug/chemical scope clearly distinguishes it from pharmgkb siblings like gene_search and variant_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?

It clearly frames the use case: lookup by drug/chemical name, with examples and a note about 3,000+ pharmacologically relevant compounds. It gives clear context but does not explicitly call out sibling alternatives or when-not-to-use scenarios.

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