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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to restate safety. It adds meaningful behavioral context: up to 10 variants per call, omission of variant names and protein changes, and a clear pricing model where failed calls are not charged.

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 front-loaded with the core resource and returned fields, then adds limits, exclusions, and pricing in compact sentences. Every sentence carries operational value for an agent deciding whether and how to call the tool.

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?

Given the simple two-parameter schema, full schema coverage, annotations, and the existence of an output schema, the description is complete for correct invocation. It covers scope, output content, limits, exclusions, and payment behavior without needing to explain return-value structure.

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 description coverage is 100%, so both the gene and max parameters are already documented in the schema. The description reinforces the gene-symbol scope and the one-to-ten limit but adds no new syntax or edge-case semantics beyond that baseline.

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 names a specific resource (NCBI ClinVar variants), the key input (human gene symbol), and the returned fields (VCV accession, variant type, germline clinical significance, last evaluation date). It clearly differentiates this clinical-variant lookup from sibling health tools such as dbSNP, GWAS, or pharmacogenetics.

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?

Usage is implied by 'for a human gene symbol' and by the stated limits, but the description does not explicitly say when to choose this tool versus alternatives like health_dbSNP_polymorphisms or health_gwas_catalog_associations. It gives useful constraints but no direct routing guidance.

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