openwebui-mcp-server

openwebui_update_function

Update an existing Open WebUI function's source code, name, or description. Pass only the fields you want to change.

Instructions

Update an existing function's source code, name, or description. Pass only the fields you want to change.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "id": "<id>"
    },
    "name": "openwebui_update_function"
  }
}

Input Schema

Name	Required	Description
`id`	Yes	Function ID to update
`name`	No	New display name (optional)
`content`	No	New Python source code (optional)
`description`	No	New description (optional)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.2Aug 10, 2026

TDQS

A3.9/5.0

Behavior2/5

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

With no annotations, the description must fully disclose behavior. It only mentions that unspecified fields remain unchanged, but does not disclose permissions, error behavior, side effects, or whether the update is atomic. This is insufficient for a mutation tool.

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 two sentences, front-loads the purpose, and contains no redundant information. Every word contributes to the user's understanding.

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 is adequate for a simple CRUD update but lacks details on return values, error conditions, or permissions. Given the absence of annotations and output schema, more context would be helpful, though the schema covers the parameters.

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?

The schema already describes all four parameters (100% coverage). The description adds value by clarifying that only the fields passed are updated, which is key partial-update semantics beyond the schema's optional flags.

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 updates an existing function's source code, name, or description, using a specific verb and resource. It distinguishes itself from sibling create/delete/list/get functions by specifying the update action and the modifiable fields.

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 that this is for updating an existing function, and the instruction to pass only the fields to change implies partial updates. However, it does not explicitly mention alternatives or when not to use this tool, though the purpose makes it reasonably clear.

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