gtex_expression

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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds meaningful behavioral detail beyond annotations: GTEx Analysis v10, 54 tissue sites, TPM units, highest-first sorting, accepted identifier formats, and tissue filter semantics. This provides useful expectations 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 two short, front-loaded paragraphs: the first states the core function and key details, the second explains accepted inputs and optional filtering. Every sentence adds information, with no filler or redundancy.

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 simple read-only lookup tool with full schema coverage and clear annotations, the description covers the essential context: data source, units, sort order, identifier acceptance, and filtering. There is no output schema, but the first sentence implies the return shape (per-tissue median expression sorted high to low), which is sufficient for this tool.

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 the parameters are already fully documented in the schema. The description reinforces the meaning of gene and tissue with examples but does not add substantial new semantics beyond what the schema provides. Baseline 3 is appropriate.

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 and resource: 'Get median gene expression across GTEx tissues', further specifying version, tissue count, units, and sort order. This clearly distinguishes it from sibling tools like gtex_eqtl and the gene_* family, which cover different biological queries.

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 gives clear usage context: accept an HGNC symbol or Ensembl gene ID, optionally filter by tissue, and return a limited number of top-expressing tissues. It does not explicitly name alternatives or state when not to use the tool, but the context is specific enough for an agent to select it appropriately.

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