macOS GUI Control MCP

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

No annotations are provided, so the description carries full burden. It mentions the action occurs 'at current cursor position', which adds some behavioral context about targeting. However, it lacks critical details: whether this simulates keyboard events, requires focus, has side effects (e.g., triggering auto-complete), or error conditions (e.g., if no cursor exists). For a mutation tool with zero annotation coverage, this is insufficient.

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 front-loads the core action ('Type text') and adds necessary context ('at current cursor position'). Every word earns its place, making it easy for an agent to parse quickly.

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 tool's complexity (a mutation action with potential side effects), no annotations, no output schema, and incomplete behavioral disclosure, the description is inadequate. It should explain more about how the typing works (e.g., simulated keystrokes), what happens on failure, or return values. The current description leaves too many gaps for reliable 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?

Schema description coverage is 100% with one parameter ('text') fully documented in the schema. The description adds no parameter-specific details beyond what the schema provides (e.g., no examples, formatting rules, or constraints). With high schema coverage, the baseline is 3, as the description doesn't compensate but doesn't need to.

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 ('type') and resource ('text'), specifying the action occurs 'at current cursor position'. It distinguishes from siblings like keyboard_press (single key) and keyboard_shortcut (key combinations), though not explicitly named. The purpose is specific but could be more explicit about sibling differentiation.

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?

No guidance on when to use this tool versus alternatives like keyboard_press or keyboard_shortcut. The description implies usage for typing arbitrary text at the cursor, but lacks explicit when/when-not instructions or prerequisites (e.g., requires an active text field). This leaves the agent to infer context from tool names alone.

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