Press Key Chord

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

The annotations already indicate non-read-only, non-destructive behavior. The description adds an authentication requirement ('Requires Accessibility permission') and clarifies the chord syntax with valid modifiers, which goes beyond the structured data. No description of return behavior, but for a simple action tool this is acceptable.

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?

Two sentences, front-loaded with the action and examples, then essential modifiers and permission note. No fluff.

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?

The description plus schema fully cover the tool's usage for a single-parameter action tool. It includes examples, modifier list, and permission requirement; no output schema is needed for a fire-and-forget key press. Sibling list also helps disambiguate.

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 schema only states 'Chord like "cmd+shift+4".' The description enriches this by listing valid modifiers (cmd, shift, alt/option, ctrl, fn) and providing additional examples for special keys ('return', 'left'), significantly improving the agent's ability to construct valid parameter values.

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 uses the specific verb 'Press' with resource 'keyboard chord' and provides concrete examples ('cmd+shift+4', 'cmd+c', 'return', 'left'), making it clear this tool sends key combinations/special keys. This differentiates it from siblings like input_type (text entry) and input_key_hold (single key hold).

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 examples and modifier list clearly imply when to use this tool (for chords and special keys), and it mentions a prerequisite (Accessibility permission). However, it does not explicitly contrast with sibling tools like input_key_hold or input_type, so it stops short of full exclusion guidance.

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