Type text

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true. The description adds valuable context beyond annotations: it requires admin mode, MACCTL_ALLOW_INPUT=true, and Accessibility permission, and it types into the frontmost app. It doesn't mention whether the text is typed at the current cursor position or whether it replaces existing content, but the permission requirements are significant 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.

Is the description appropriately sized, front-loaded, and free of redundancy?

One sentence, front-loaded with the core action ('Type literal text into the frontmost app'), followed immediately by the critical prerequisites. Every word earns its place; no fluff or repetition of the schema.

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?

For a single-parameter tool with a 100% schema coverage and no output schema, the description covers the action, target, and prerequisites. It doesn't explain what happens on failure (e.g., if permissions are missing) or whether the text is typed at the cursor position, but these are minor gaps given the tool's simplicity and the annotation coverage.

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% — the only parameter 'text' is described as 'Text to type.' The description adds the nuance that the text is 'literal' and typed as 'keystrokes,' which is slightly more than the schema provides, but the schema already fully documents the parameter. Baseline 3 is appropriate.

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 states a specific verb ('Type'), a specific resource ('literal text'), and a specific target ('frontmost app'), and clarifies it operates via keystrokes. This clearly distinguishes it from siblings like key_press (which sends individual key combinations) and set_clipboard (which sets clipboard content).

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 explicitly states the prerequisites for use: admin mode, MACCTL_ALLOW_INPUT=true, and Accessibility permission. It doesn't explicitly name alternatives or say when not to use it, but the prerequisites and the 'literal text' qualifier give clear context for when this tool is appropriate versus key_press or set_clipboard.

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