Medical Terminologies MCP

ICD-11 Postcoordination Options

icd11_postcoordination

Read-onlyIdempotent

Check which postcoordination axes an ICD-11 stem code accepts, including required vs optional and value counts, before building composite codes.

Instructions

List the postcoordination axes WHO allows for one ICD-11 stem code (MMS linearization, pinned release).

Postcoordination means attaching extra detail to a stem code — severity, laterality, anatomy, causing agent, etc. — to build a composite (cluster) code.

Use this tool to:

See which axes a stem code accepts before building a composite code
Check which axes are REQUIRED vs optional
See whether an axis takes one or several values, and how many values it offers

Provide an ICD-11 code (e.g., "BA00"). Returns one entry per axis with axis_name, required, allow_multiple and value_count — the count of allowed values, not the values themselves. A code with no postcoordination, or one WHO does not know, returns an empty axes list (not an error), so check the code with icd11_lookup if the list is unexpectedly empty.

When NOT to use: this does not build or validate a composite code, and it does not list the allowed values; to get a code from a disease name, use icd11_search.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`code`	Yes	ICD-11 code to get postcoordination info for

Output Schema

TableJSON Schema

Name	Required	Description
`axes`	Yes
`code`	Yes
`provenance`	Yes	Provenance block (contract v1.1): source, URL, data vintage, extraction instant, origin diagnostics, citation, license
`attribution`	Yes	Canonical source URLs of this response (attribution list)

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv1.15.0Sep 27, 2026

changedOutput schema / properties / provenance / description

Previous value: -"Provenance block (contract v1.0): source, URL, data vintage, extraction instant, citation, license"New value: +"Provenance block (contract v1.1): source, URL, data vintage, extraction instant, origin diagnostics, citation, license"

addedOutput schema / properties / provenance / properties / retrieval

Added value: +{
+  "anyOf": [
+    {
+      "additionalProperties": false,
+      "properties": {
+        "anomalies": {
+          "description": "Anomalias superadas até o sucesso, somadas por classe, em ordem fixa; [] se nenhuma",
+          "items": {
+            "additionalProperties": false,
+            "properties": {
+              "count": {
+                "description": "Ocorrências desta classe na chamada",
+                "maximum": 9007199254740991,
+                "minimum": 1,
+                "type": "integer"
+              },
+              "kind": {
+                "description": "Classe da anomalia (vocabulário fechado do contrato)",
+                "enum": [
+                  "timeout",
+                  "network",
+                  "http_4xx",
+                  "http_5xx",
+                  "rate_limited",
+                  "malformed_body"
+                ],
+                "type": "string"
+              }
+            },
+            "required": [
+              "kind",
+              "count"
+            ],
+            "type": "object"
+          },
+          "type": "array"
+        },
+        "attempts": {
+          "description": "Tentativas somadas, incluindo as repetidas (>= requests)",
+          "maximum": 9007199254740991,
+          "minimum": 1,
+          "type": "integer"
+        },
+        "requests": {
+          "description": "Idas distintas à origem que compõem esta resposta (fatias, páginas)",
+          "maximum": 9007199254740991,
+          "minimum": 1,
+          "type": "integer"
+        },
+        "unstable": {
+          "description": "true se houve repetição (attempts > requests) ou alguma anomalia",
+          "type": "boolean"
+        }
+      },
+      "required": [
+        "requests",
+        "attempts",
+        "anomalies",
+        "unstable"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "description": "Origin diagnostics of THIS source in this call (contract v1.1): requests made to the upstream, attempts summed across retries, anomalies worked around (kind + count); unstable=true when any anomaly happened. null when nothing was measured (bundled dataset, or response served entirely from cache)"
+}

changedOutput schema / properties / provenance / required

Previous value: -[
-  "source",
-  "source_url",
-  "data_vintage",
-  "retrieved_at",
-  "citation",
-  "license"
-]New value: +[
+  "source",
+  "source_url",
+  "data_vintage",
+  "retrieved_at",
+  "retrieval",
+  "citation",
+  "license"
+]

Changed1 schema field changedv1.11.0Sep 15, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```
Changed4 schema fields changedv1.9.1Sep 1, 2026
- removedOutput schema / properties / provenance / properties / data_vintage / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / provenance / properties / data_vintage / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / provenance / properties / license / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / provenance / properties / license / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Changed3 schema fields changedv1.8.0Aug 10, 2026

addedOutput schema / properties / attribution

Added value: +{
+  "description": "Canonical source URLs of this response (attribution list)",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

addedOutput schema / properties / provenance

Added value: +{
+  "additionalProperties": false,
+  "description": "Provenance block (contract v1.0): source, URL, data vintage, extraction instant, citation, license",
+  "properties": {
+    "citation": {
+      "description": "Ready-to-use citation/attribution string",
+      "type": "string"
+    },
+    "data_vintage": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "description": "Version/release of the data as exposed by the source; null when not exposed"
+    },
+    "license": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "description": "License / legal regime of the data"
+    },
+    "retrieved_at": {
+      "description": "Real instant of the upstream extraction (ISO-8601, UTC). Responses served from cache keep the ORIGINAL fetch instant.",
+      "type": "string"
+    },
+    "source": {
+      "description": "Official upstream source of this data",
+      "type": "string"
+    },
+    "source_url": {
+      "description": "Canonical URL of the source (API base or dataset release)",
+      "type": "string"
+    }
+  },
+  "required": [
+    "source",
+    "source_url",
+    "data_vintage",
+    "retrieved_at",
+    "citation",
+    "license"
+  ],
+  "type": "object"
+}

changedOutput schema / required

Previous value: -[
-  "code",
-  "axes"
-]New value: +[
+  "code",
+  "axes",
+  "provenance",
+  "attribution"
+]

Changed2 schema fields changedv1.5.7Jun 21, 2026

removedInput schema / additionalProperties
```
Removed value: -false
```

changedOutput schema / properties / axes / items / properties / value_count / anyOf

Previous value: -[
-  {
-    "type": "integer"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "maximum": 9007199254740991,
+    "minimum": -9007199254740991,
+    "type": "integer"
+  },
+  {
+    "type": "null"
+  }
+]

First observedv1.2.1May 11, 2026

TDQS

A4.7/5.0

Behavior4/5

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior: an empty axes list is not an error, and it clarifies that value_count is a count rather than the values. It does not add much beyond what the output schema likely shows.

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?

Front-loaded definition of the term followed by bulleted use cases and a clear negative clause. Every sentence earns its place and the structure is easy to scan.

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?

An output schema exists, yet the description still summarizes the returned fields and the empty-list edge case. Combined with annotations and full schema coverage, an agent has everything needed to call it correctly.

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 coverage is 100% for the single parameter, so the baseline is 3. The description adds a concrete format example ("BA00") and confirms the parameter is the ICD-11 stem code, which marginally improves on the schema.

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?

States a specific verb (List) and resource (postcoordination axes) scoped to one ICD-11 stem code in a named linearization/release. It clearly differentiates from siblings by noting it does not build/validate composites or list values, unlike icd11_lookup/icd11_search.

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

Usage Guidelines5/5

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

Explicit use cases (check accepted axes, required vs optional, single/multi-value counts) plus an explicit 'When NOT to use' section naming alternatives (icd11_search for disease name, icd11_lookup when the list is empty). Nothing is left to inference.

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