da_key

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

No annotations are provided, so the description carries the burden of behavioral disclosure. The description does explain the holdMs behavior ('holdMs > 0 issues a press-hold-release'), which is useful. However, it does not disclose what happens with a plain press (does it release immediately?), whether the tool blocks until the key event completes, or what the return value is. The description adds some behavioral context beyond the bare schema.

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 that covers the purpose, modifiers usage with a concrete example, and the holdMs behavior. No wasted words, front-loaded with the core verb+resource. Could arguably be slightly fuller but is appropriately concise for a simple key-press tool.

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?

This is a relatively simple 3-parameter tool with no output schema and no annotations. The description explains modifiers and holdMs behavior via the example and the holdMs sentence. It doesn't explain the default behavior when holdMs is absent (0), whether repeated presses are supported, or what the return value contains. For a simple tool it's mostly adequate but leaves some ambiguity about default press behavior.

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 0%, so the description must carry the weight for parameter meaning. The description names all three parameters ('key', 'modifiers', 'holdMs') and explains two of them in prose. The modifiers example (Ctrl+C mapping) adds practical meaning, and the holdMs semantics are explicit. Only the exact 'key' naming convention (e.g., how special keys like Enter or arrows are referenced) is left underspecified.

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 the action clearly: 'Press a key by name, optionally with modifiers.' The verb+resource is specific and understandable. It doesn't explicitly differentiate from sibling tools like da_type (which types text vs presses keys), but given the sibling set includes da_click, da_double_click, da_drag, da_scroll, da_type, the distinct purpose of pressing a key by name is reasonably evident from context.

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 implies its usage context (press individual keys, shortcuts with modifiers) and gives a concrete example. However, it doesn't explicitly say when NOT to use it versus da_type (which presumably types strings of characters) or when a modifier combination is preferred over separate presses. The when-versus-alternatives guidance is implied rather than explicit.

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