Skip to main content
Glama

mister_cfg_write

Modify MiSTer FPGA core settings by specifying option name and value. Automatically creates a backup of the CFG file before each write. Combine with cfg_read and mister_reload for full control.

Instructions

Set a core option by name and value. Automatically backs up the CFG file before writing. Use cfg_read first to see available options and their current values. Example: option='Free Play', value='On'. After writing, use mister_reload to apply changes.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
optionYesOption name (e.g. 'Aspect Ratio', 'Free Play', 'Region')
valueYesValue name (e.g. 'Original', 'On', 'US')
Behavior4/5

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

Discloses that it 'automatically backs up the CFG file before writing', providing useful behavioral context. No annotations exist, so description carries full burden; it also mentions the need to apply changes via reload. Lacks details on error handling or permissions, but adequate.

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?

Three sentences: purpose, backup behavior, usage guidance with example. No fluff, every sentence adds value, well-structured.

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

Completeness4/5

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

Covers purpose, usage, behavior, and post-action. No output schema, so return value explanation not required. Could mention handling of invalid inputs, but overall complete for a simple write tool.

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?

Schema coverage is 100% (both parameters described in the schema). Description adds concrete examples ('option='Free Play', value='On'') and explains the pattern, adding value beyond the schema.

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 uses a specific verb ('Set') and resource ('core option by name and value'), clearly distinguishing it from the sibling tool 'mister_cfg_read' which is for reading.

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?

Explicitly advises to use 'cfg_read first to see available options and their current values', and provides an example and post-write action ('use mister_reload'). Missing explicit when-not-to-use, but context is clear.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/catallo/misterclaw'

If you have feedback or need assistance with the MCP directory API, please join our Discord server