press_key

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

With no annotations, the description explains the core behavior: single keys and combinations, with the detail that all keys in a combination are held together and released in reverse order. The repeat parameter is also clarified. However, it does not specify system-wide vs. focused-window behavior or error handling, which would add completeness.

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 extremely concise with no wasted words. It uses bullet-style formatting for examples and clearly separates single vs. combination keys. Every sentence adds value.

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 low complexity (2 simple parameters, no nested objects), the description covers the essential functionality well. It explains key behavior and parameter usage. Could optionally mention that the tool requires an active window, but the description is sufficiently complete for a key-press tool.

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 0% description coverage, so the description fully compensates. It explains the 'keys' parameter with clear examples of both single strings and list combinations, and clarifies that 'repeat' defaults to 1. This adds significant value beyond the bare schema.

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 tool presses a key or key combination, with specific examples of single keys and combination lists. It effectively distinguishes from siblings like 'type_text' (typing strings) or 'click' (mouse actions).

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 valid key examples and explains how combinations work (held together, reverse release), but does not explicitly guide when to use this tool vs. alternatives like 'type_text' for typing or 'focus' for activation. Implicit usage is clear but lacks explicit context for selection.

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