MIDL MCP Server

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midl_write_contract

Destructive

Execute a state-changing function on a smart contract using the MIDL intention flow. Supports payable functions with value parameter in wei.

Instructions

Execute a state-changing function on a smart contract via MIDL intention flow. For payable functions, include value parameter (in wei).

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": {
      "address": "<address>",
      "abi": "<abi>",
      "functionName": "<functionName>"
    },
    "name": "midl_write_contract"
  }
}

Input Schema

Name	Required	Description
`address`	Yes	Contract address
`abi`	Yes	Contract ABI (JSON array)
`functionName`	Yes	Function name to call
`args`	No	Function arguments
`value`	No	BTC value to send (in wei) for payable functions

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0May 25, 2026

TDQS

B3.4/5.0

Behavior3/5

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

Annotations already indicate destructiveHint=true and readOnlyHint=false. The description adds that it is state-changing and mentions value for payable functions, which is consistent but adds minimal new behavioral context.

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?

Two concise sentences front-loaded with the primary action and key usage detail (payable functions need value). No redundancy.

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?

Lacks explanation of return values, error handling, or safety warnings for a destructive tool. Does not clarify 'MIDL intention flow' or what happens on failure.

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

Parameters3/5

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

Schema coverage is 100%, so all parameters have descriptions. The description provides context about payable functions needing value, which reinforces the schema's value field description but does not add new parameter semantics.

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

Purpose4/5

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

The description clearly states it executes a state-changing function on a smart contract, which distinguishes it from read tools. However, it does not explicitly differentiate from other write tools like deploy or transfer, but the name and context are sufficient.

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?

The description provides guidance for payable functions (include value parameter), but lacks when-to-use versus alternatives (e.g., deploy, transfer) or any exclusions.

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