computer-use-mac-mcp

hold_key

Hold one or more keyboard keys for a specified duration to trigger shortcuts, key combinations, or press-and-hold actions in macOS automation.

Instructions

Hold one or more keys for a duration.

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": {
      "key": "<key>"
    },
    "name": "hold_key"
  }
}

Input Schema

Name	Required	Description	Default
`key`	Yes	Key name to hold
`duration_ms`	No	Duration in milliseconds (default 1000)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 30, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full burden, but it only states the core action. It does not disclose whether the key is automatically released after the duration, whether multiple keys are passed in a single string, or what side effects holding may have.

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 concise, front-loaded sentence with no filler. It could be slightly improved by replacing 'one or more keys' with a concrete parameter example, but it is appropriately short.

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?

For an unannotated tool with no output schema, the description is minimal. An agent can infer the basic action, but it is not told how to express multiple keys, what happens at the end of the duration, or how this tool relates to the sibling 'key' tool.

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 description coverage is 100%, so the schema already explains 'key' and 'duration_ms'. The description's claim of 'one or more keys' adds a hint, but it conflicts with the singular 'Key name to hold' parameter, creating ambiguity rather than clarity.

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 identifies a concrete action—holding keys for a duration—and clearly names the resource ('keys'). It is distinct from the sibling 'key' in that it emphasizes holding rather than pressing, but it does not explicitly call out that distinction.

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

Usage Guidelines2/5

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

No guidance is given about when to use hold_key instead of the sibling 'key' tool or any other alternative. The context of keyboard vs mouse actions is inferable, but the description leaves the selection criteria completely implicit.

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

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