OpenRouter MCP Multimodal Server

chat_completion

Send messages to an OpenRouter model and retrieve responses. Supports system, user, assistant roles with optional model, temperature, and token limits.

Instructions

Send messages to an OpenRouter model and get a response

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": {
      "messages": "<messages>"
    },
    "name": "chat_completion"
  }
}

Input Schema

Name	Required	Description
`model`	No	Model ID (optional, uses default)
`messages`	Yes
`max_tokens`	No
`temperature`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.8.2Apr 2, 2026

TDQS

B3.2/5.0

Behavior2/5

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false. The description adds no extra behavioral context such as token consumption, cost, or response format. For a mutation tool, this is insufficient transparency.

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 a single, clear sentence with no extraneous information. It is front-loaded with the core action, but could benefit from mentioning key parameters.

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

Completeness2/5

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

The tool has multiple parameters and nested objects, but the description omits details on response format, error handling, streaming, or any limitations. Without an output schema, the description should provide more context to be 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?

Schema coverage is low (25%), and the description does not explain individual parameters like temperature or max_tokens. It only implies 'model' and 'messages' are used. The description fails to compensate for the schema's lack of detail.

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 verb 'Send messages' and the resource 'OpenRouter model', directly conveying the tool's function. It distinguishes from sibling tools like analyze_audio or generate_image, which have different modalities.

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

Usage Guidelines3/5

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

No explicit guidance on when or when not to use this tool versus alternatives. The verb 'chat' implies it is for conversational interactions, but no mention of situations where other tools (e.g., analyze_image) would be more appropriate.

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

Deploy Server