Illumio MCP Server

update-label

Update an existing label in the Illumio PCE by providing its href or key/value pair along with a new value to modify the label.

Instructions

Update an existing label in the PCE. Provide either: 1) href + new_value (optionally with key), or 2) key + value + new_value to identify and update the label. WRITE OPERATION: changes PCE state. In clients that gate tool calls (Claude Desktop, Claude Code), this pauses for the user to approve it -- the call has not failed and must not be retried while waiting.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "update-label"
  }
}

Input Schema

Name	Required	Description
`key`	No	Label type (e.g., role, app, env, loc). Required when using value to identify label, or when using href.
`href`	No	Label href (e.g., /orgs/1/labels/42). Use this to directly identify the label.
`value`	No	Current value of the label. Used with key to identify the label when href is not provided.
`new_value`	No	New value for the label. Always required.

Schema Changelog

Changes observed during successful MCP inspections.

Changed5 schema fields changedv0.8.0Sep 18, 2026

removedInput schema / oneOf

Removed value: -[
-  {
-    "required": [
-      "href",
-      "key",
-      "new_value"
-    ]
-  },
-  {
-    "required": [
-      "key",
-      "value",
-      "new_value"
-    ]
-  }
-]

changedInput schema / properties / href / description

Previous value: -"Label href (e.g., /orgs/1/labels/42). Either href or both key and value must be provided to identify the label."New value: +"Label href (e.g., /orgs/1/labels/42). Use this to directly identify the label."

changedInput schema / properties / key / description

Previous value: -"Label type (e.g., role, app, env, loc)"New value: +"Label type (e.g., role, app, env, loc). Required when using value to identify label, or when using href."

changedInput schema / properties / new_value / description

Previous value: -"New value for the label"New value: +"New value for the label. Always required."

changedInput schema / properties / value / description

Previous value: -"Current value of the label"New value: +"Current value of the label. Used with key to identify the label when href is not provided."

Addedv1.0.0Jan 2, 2026

TDQS

A4.1/5.0

Behavior5/5

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly flags 'WRITE OPERATION: changes PCE state,' and crucially warns that approval-gated clients may pause and that the call must not be retried while waiting. This non-obvious, actionable behavior goes well beyond what the schema conveys.

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

Conciseness4/5

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

The description is compact and front-loaded: purpose, invocation methods, then the critical write/approval warning. Each sentence earns its place. It loses a point for the misleading 'optionally with key' phrasing, which introduces ambiguity in an otherwise efficient structure.

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

Completeness3/5

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

The description covers the core purpose, invocation options, and a key behavioral warning, which is substantial. However, the key/href contradiction creates a real gap that could prevent correct invocation. It also does not mention what happens on success or how to handle cases where both identification methods are provided, making it minimally viable but not complete.

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

Parameters2/5

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

Although schema coverage is 100%, the description's parameter guidance contradicts the schema: it says href + new_value is used 'optionally with key,' while the schema states key is required when using href. This conflicting instruction can mislead an agent into constructing an invalid call. The description also does not clarify precedence if both href and key+value are supplied, so it subtracts value rather than adding it.

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 opens with a specific verb and resource: 'Update an existing label in the PCE.' This clearly distinguishes it from siblings like create-label, delete-label, and get-labels. It further clarifies the resource scope and that only existing labels are affected.

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 two explicit identification methods (href-based and key+value-based) and states that new_value is always required. This gives clear context on how to invoke the tool. However, it does not explicitly state when not to use it, such as pointing to create-label for new labels or delete-label for removals, so it falls short of a 5.

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

Deploy Server