Open WebUI MCP Server

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

No annotations are provided, so the description carries full burden. It states this is an update operation, implying mutation, but doesn't disclose behavioral traits like required permissions, whether changes are reversible, rate limits, or what happens to unspecified fields (e.g., if they remain unchanged). The description is minimal and lacks critical context 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.

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

The description is a single, efficient sentence with zero waste. It's front-loaded with the core action and resource, and every word ('Update a model's name, system prompt, or parameters') directly contributes to understanding the tool's purpose without redundancy.

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

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

Given the complexity (a mutation tool with 1 parameter that is a nested object), no annotations, and an output schema (which reduces need to describe returns), the description is incomplete. It covers the basic purpose but lacks guidelines, behavioral details, and full parameter explanation. It's minimally adequate but has clear gaps for safe and correct usage.

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

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

Schema description coverage is 0%, so the schema provides no parameter descriptions. The description mentions 'name, system prompt, or parameters', which partially maps to the nested properties (name, system_prompt, temperature, max_tokens) but doesn't explain the 'model_id' requirement or the structure of the 'params' object. It adds some meaning but doesn't fully compensate for the lack of schema documentation.

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

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

The description clearly states the action ('Update') and resource ('a model'), specifying what can be updated ('name, system prompt, or parameters'). It distinguishes from siblings like 'create_model' (creation vs. update) and 'delete_model' (destructive vs. modification). However, it doesn't explicitly differentiate from other update tools like 'update_prompt' or 'update_tool' beyond the resource type.

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

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

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an existing model ID), when not to use it (e.g., for creation vs. update), or refer to sibling tools like 'create_model' for initial setup or 'get_model' for checking current values. Usage is implied by the verb 'Update' but lacks explicit context.

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