nex_browser_key_down

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 key behavioral trait — the key remains held until nex_browser_key_up is called — which is useful. But it omits whether the hold state is per-session, what happens if key_up is never called, and whether focus is required.

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?

A single sentence that front-loads the core behavior and the release mechanism. No wasted words.

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 stateful keyboard tool with no annotations and no output schema, the description covers the essential pairing with key_up but leaves out key format, focus requirements, and failure behavior. It is minimally adequate but not complete.

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 coverage is 67%: pageId and sessionId are documented in the schema, but the required key parameter has no description. The tool description adds no format guidance (e.g., 'Enter', 'a', modifier keys), leaving a critical gap for the primary parameter.

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 a specific verb (hold) and resource (keyboard key), and names the paired release tool nex_browser_key_up. It distinguishes itself from a simple press by describing a persistent hold. Sibling differentiation is present but not exhaustive against press_key or type.

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?

It implies the usage pattern: call this and then call nex_browser_key_up to release. However, it doesn't say when to choose this over nex_browser_press_key or nex_browser_type, nor does it state prerequisites like page focus.

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