Gtex

Top Expressed Genes

top_expressed_genes

Read-onlyIdempotent

GTEx Portal (Genotype-Tissue Expression project) — the genes with the highest median expression in one human tissue, given a GTEx tissueSiteDetailId such as Liver or Whole_Blood. Returns ranked genes with Gencode id, gene symbol and median TPM, with a settable result count and an optional mitochondrial-gene filter. Answers which genes are most highly expressed in human liver, brain or blood.

Input Schema

TableJSON Schema

Name	Required	Description
`num`	No	1-1000 (default 50).
`tissue`	Yes	GTEx tissueSiteDetailId (e.g. "Liver", "Whole_Blood")
`datasetId`	No	gtex_v8 (default) \| gtex_v10
`filter_mt_gene`	No	Exclude mitochondrial genes (default true).

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

Changed2 schema fields changedMay 22, 2026

addedInput schema / examples

Added value: +[
+  {
+    "tissue": "Whole_Blood"
+  },
+  {
+    "datasetId": "gtex_v10",
+    "filter_mt_gene": false,
+    "num": 100,
+    "tissue": "Liver"
+  }
+]

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "description": "Top expressed genes for a specified tissue",
+  "type": "object"
+}

First observedMay 18, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds valuable context about the output (ranked genes with Gencode id, gene symbol, median TPM), the optional mitochondrial filter, and the configurable result count, going beyond the annotations without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three focused sentences. The first sentence establishes the tool's core function, the second details the output, and the third gives a concrete use case. No wasted words or redundancy with the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a four-parameter read-only tool with full schema coverage and an output schema, the description covers the essential aspects: what it does, what it returns, example inputs, and an optional filter. It is complete enough for an agent to invoke correctly without further clarification.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so each parameter is already described. The description reinforces the meaning of 'tissue' and mentions the result count and mitochondrial filter, but does not provide significant additional semantic detail beyond the schema. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool returns the genes with the highest median expression in a specified human tissue, using a specific verb ('returns') and resource (GTEx Portal). It differentiates from siblings like median_expression by emphasizing ranking by median TPM and providing concrete examples (Liver, Whole_Blood).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context for when to use the tool ('answers which genes are most highly expressed in human liver, brain or blood') and explains the required tissueSiteDetailId format. It does not explicitly name alternatives or exclusions, but the use case is well implied.

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

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