kegg-mcp-server

get_reaction_info

Read-onlyIdempotent

Retrieve KEGG reaction details by reaction ID, choosing summary or full detail to inspect reaction equations and related annotations.

Instructions

Get detailed information for a KEGG reaction.

Args: reaction_id: KEGG reaction ID (e.g. 'R00756' for glucose phosphorylation). detail_level: 'summary' (default, compact) or 'full' (complete flat-file parse).

Input Schema

Name	Required	Description	Default
`reaction_id`	Yes
`detail_level`	No		summary

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv0.5.0Oct 23, 2026

addedOutput schema / $defs / EntrySummary / properties / symbol

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Symbol"
+}

removedOutput schema / $defs / ErrorResult

Removed value: -{
-  "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"
-}

addedOutput schema / $defs / Reference / properties / sequence

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Sequence"
+}

changedOutput schema / properties / result / anyOf

Previous value: -[
-  {
-    "$ref": "#/$defs/ReactionInfo"
-  },
-  {
-    "$ref": "#/$defs/EntrySummary"
-  },
-  {
-    "$ref": "#/$defs/ErrorResult"
-  }
-]New value: +[
+  {
+    "$ref": "#/$defs/ReactionInfo"
+  },
+  {
+    "$ref": "#/$defs/EntrySummary"
+  }
+]

First observedv0.1.0Jul 29, 2026

TDQS

A3.9/5.0

Behavior4/5

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

Annotations already cover safety and idempotency, but the description adds useful behavioral context by explaining that detail_level controls output depth: 'summary' is compact and 'full' is a complete flat-file parse. It does not discuss rate limits or error behavior, but those are not critical for this simple read-only lookup.

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 short, front-loaded, and structured as a clear purpose statement followed by parameter documentation. Every sentence and example earns its place.

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

Completeness4/5

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

For a simple two-parameter read-only lookup with annotations and an output schema, the description is largely complete. The main gap is the lack of explicit routing guidance versus search or pathway-based sibling tools.

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 compensate, and it does: reaction_id is explained with an example format, and detail_level is documented with its default and the meaning of each enum value. It could add stricter ID-format guidance, but the key semantics are covered.

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: 'Get detailed information for a KEGG reaction.' It clearly identifies the tool as a detail-fetch operation by reaction ID, though it does not explicitly distinguish itself from sibling tools like search_reactions or get_pathway_reactions.

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?

Usage is only implied through the required reaction_id parameter and detail_level choices. The description does not state when to use this tool instead of search_reactions or get_pathway_reactions, nor does it mention prerequisites such as needing an existing KEGG reaction ID.

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