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. 'Delete' implies a destructive mutation, but it lacks details on permissions, reversibility, side effects, or rate limits. The description is minimal and doesn't add meaningful behavioral context beyond the obvious action.

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, direct sentence with no wasted words, making it highly concise and front-loaded. Every part contributes to the core purpose without unnecessary elaboration.

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 a destructive tool with no annotations, 0% schema coverage, but an output schema exists, the description is incomplete. It covers the basic action but lacks critical details like error handling or return values, though the output schema may mitigate some gaps. It's minimally viable but has clear deficiencies.

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%, but the description mentions 'a message from a channel', hinting at the need for identifiers. It doesn't specify parameters like 'channel_id' or 'message_id' or their formats, offering only vague context. With one parameter (a nested object), this provides minimal compensation for the schema gap.

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 ('Delete') and the resource ('a message from a channel'), making the purpose immediately understandable. It doesn't distinguish from siblings like 'delete_channel' or 'delete_chat', but the specificity of 'channel message' is adequate for basic clarity.

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?

No guidance is provided on when to use this tool versus alternatives. With siblings like 'delete_channel' and 'delete_chat', there's no indication of context, prerequisites, or exclusions, leaving the agent to infer usage based on naming alone.

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