kegg-mcp-server

search_diseases

Read-onlyIdempotent

Find diseases in the KEGG database by name or keyword. Provide a query and optional max results (up to 100) to get matching disease records.

Instructions

Search KEGG diseases by name or keyword.

Args: query: Disease name (e.g. 'diabetes', 'cancer', 'Alzheimer'). max_results: Maximum number of results to return (capped at 100).

Input Schema

Name	Required	Description	Default
`query`	Yes
`max_results`	No

Output Schema

Name	Required	Description	Default
`query`	Yes
`results`	Yes
`database`	Yes
`truncated`	No
`total_found`	Yes
`returned_count`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed10 schema fields changedv0.5.0Oct 23, 2026

removedOutput schema / $defs

Removed value: -{
-  "ErrorResult": {
-    "description": "Structured error returned by a tool when the KEGG API fails.\n\nA tool returns this instead of raising so the model can reason about\nthe failure and decide whether to retry, change inputs, or give up.\nA point lookup that receives a 404 uses code ``not_found``; an empty search\nremains a successful result with no items.",
-    "properties": {
-      "code": {
-        "default": "kegg_api_error",
-        "title": "Code",
-        "type": "string"
-      },
-      "error": {
-        "title": "Error",
-        "type": "string"
-      },
-      "hint": {
-        "anyOf": [
-          {
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "title": "Hint"
-      },
-      "path": {
-        "anyOf": [
-          {
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "title": "Path"
-      },
-      "retryable": {
-        "default": false,
-        "title": "Retryable",
-        "type": "boolean"
-      },
-      "status": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "title": "Status"
-      }
-    },
-    "required": [
-      "error"
-    ],
-    "title": "ErrorResult",
-    "type": "object"
-  },
-  "SearchResult": {
-    "properties": {
-      "database": {
-        "title": "Database",
-        "type": "string"
-      },
-      "query": {
-        "title": "Query",
-        "type": "string"
-      },
-      "results": {
-        "additionalProperties": {
-          "type": "string"
-        },
-        "title": "Results",
-        "type": "object"
-      },
-      "returned_count": {
-        "title": "Returned Count",
-        "type": "integer"
-      },
-      "total_found": {
-        "title": "Total Found",
-        "type": "integer"
-      },
-      "truncated": {
-        "default": false,
-        "title": "Truncated",
-        "type": "boolean"
-      }
-    },
-    "required": [
-      "query",
-      "database",
-      "total_found",
-      "returned_count",
-      "results"
-    ],
-    "title": "SearchResult",
-    "type": "object"
-  }
-}

addedOutput schema / properties / database

Added value: +{
+  "title": "Database",
+  "type": "string"
+}

addedOutput schema / properties / query

Added value: +{
+  "title": "Query",
+  "type": "string"
+}

removedOutput schema / properties / result

Removed value: -{
-  "anyOf": [
-    {
-      "$ref": "#/$defs/SearchResult"
-    },
-    {
-      "$ref": "#/$defs/ErrorResult"
-    }
-  ],
-  "title": "Result"
-}

addedOutput schema / properties / results

Added value: +{
+  "additionalProperties": {
+    "type": "string"
+  },
+  "title": "Results",
+  "type": "object"
+}

addedOutput schema / properties / returned_count

Added value: +{
+  "title": "Returned Count",
+  "type": "integer"
+}

addedOutput schema / properties / total_found

Added value: +{
+  "title": "Total Found",
+  "type": "integer"
+}

addedOutput schema / properties / truncated

Added value: +{
+  "default": false,
+  "title": "Truncated",
+  "type": "boolean"
+}

changedOutput schema / required

Previous value: -[
-  "result"
-]New value: +[
+  "query",
+  "database",
+  "total_found",
+  "returned_count",
+  "results"
+]

changedOutput schema / title

Previous value: -"search_diseasesOutput"New value: +"SearchResult"

First observedv0.1.0Jul 29, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare this as a safe, idempotent, non-destructive open-world read operation. The description adds useful behavioral detail beyond annotations, notably that results are capped at 100 and that matching is by disease name or keyword.

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?

The description is front-loaded with the core operation and then briefly explains both arguments. There is no redundant or wasted text.

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 simple two-parameter search tool, the description covers the operation and parameter semantics sufficiently. Return-value details are not needed because an output schema exists, and annotations already supply the safety and openness profile.

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

Parameters4/5

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

Schema description coverage is 0%, so the description must carry parameter meaning; it does document both parameters, including examples for query and the cap for max_results. It could be stronger by noting case behavior or default behavior, but it adequately compensates for the schema gap.

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

Purpose4/5

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

The description states a specific verb and resource: searching KEGG diseases by name or keyword. It is clear enough to distinguish from detail-retrieval siblings like get_disease_info, but it does not explicitly name or contrast with that sibling.

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

Usage Guidelines3/5

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

The search-oriented wording implies when to use this tool, and the query examples make the intended input clear. However, it gives no explicit when-to-use versus get_disease_info guidance or when-not-to-use conditions.

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