macOS GUI Control MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'execute' but doesn't clarify what that entails—e.g., whether it simulates key presses, requires focus on a specific application, has side effects, or returns any output. This leaves significant gaps in understanding the tool's behavior.

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, efficient sentence with zero waste—it directly states the tool's action without unnecessary elaboration. It's appropriately sized and front-loaded for quick understanding.

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 the complexity of simulating keyboard shortcuts (which can have varied effects across applications) and the lack of annotations and output schema, the description is insufficient. It doesn't address behavioral nuances, return values, or error handling, making it incomplete for effective agent use.

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?

The input schema has 100% description coverage, with the 'shortcut' parameter well-documented via an enum. The description adds no additional meaning beyond the schema, such as explaining the context or effects of each shortcut. Baseline 3 is appropriate since the schema does the heavy lifting.

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 verb 'execute' and the resource 'common keyboard shortcut', making the purpose understandable. However, it doesn't differentiate from sibling tools like 'keyboard_press' or 'keyboard_type', which might handle similar keyboard interactions but in different ways.

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?

The description provides no guidance on when to use this tool versus alternatives like 'keyboard_press' or 'keyboard_type', nor does it specify context or prerequisites. It merely states what it does without helping the agent choose appropriately among siblings.

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