press_key

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

No annotations are provided, so the description carries the burden. It discloses the core behavior (pressing keys together as a chord at the current focus) and gives examples. However, it doesn't reveal potential side effects, whether keys can be special/unsupported, whether the action blocks, or behavior when nothing is focused. For a relatively simple input tool the disclosure is adequate but thin.

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 compact sentence with useful inline examples. It's front-loaded and every word earns its place. Slightly could be more structured but at this length it's concise and clear.

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 low-complexity tool with 2 params (1 required), full schema coverage, and no output schema, the description is fairly adequate. It explains the core action and gives examples. However, it's missing guidance that would help an agent decide when keyboard input is appropriate vs type_text, and doesn't hint at what key names are valid (which could matter since keys array has free-form strings). The tab_id parameter's purpose (identifying which context) is left to schema only.

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%, so the schema documents both parameters fully (keys with items description, tab_id as optional). The description adds the chord concept ('press together') and example key names, which enriches the keys parameter slightly. But it adds nothing beyond what the schema provides for tab_id. Baseline 3 is appropriate given full schema coverage.

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 and resource: 'Press a key or chord at the current focus.' It gives concrete examples (['Enter'], ['Control','a']) that clarify the action. However, it doesn't explicitly differentiate from sibling tools like click or type_text, though the distinct action (keyboard input vs clicking) is reasonably self-evident.

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 doesn't explain when to use press_key vs alternatives like type_text or click. It mentions 'at the current focus' which implies it operates on the currently focused element, but gives no guidance on prerequisites (e.g., needing a focused element/tab first), no comparison with type_text, and no exclusions. The context is implied but not explicit.

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