Press Keyboard Key

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

The description adds crucial context beyond annotations by stating 'key presses can submit data, trigger shortcuts, navigate, or mutate remote state,' aligning with destructiveHint: true and readOnlyHint: false. It does not contradict any annotations.

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?

Three sentences, each serving a distinct purpose: when to use, preconditions and next steps, and sensitivity. No redundant or irrelevant information.

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 covers purpose, preconditions, side effects, and follow-up actions. An output schema exists (not shown), so return value explanation is not required. However, it lacks detail on all four parameters, particularly delayMs and timeoutMs, leaving some gaps for an agent.

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 compensate. It mentions 'key' implicitly via examples (Enter, Escape, Tab) and 'selector' as optional, but does not explain delayMs or timeoutMs, leaving their purpose ambiguous. More parameter detail is needed.

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 'Use when a keyboard action such as Enter, Escape, Tab, or a shortcut is part of the browser reproduction,' specifying both the verb and resource. It distinguishes from siblings like browser_click (mouse clicks) and browser_type (text input).

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 provides explicit preconditions ('an active page is required and the optional selector must identify the intended focus target') and suggests subsequent actions ('continue the sequence or inspect any resulting navigation, dialog, DOM, or network activity'). While it doesn't explicitly list exclusions or alternatives, the context implies when to use this tool vs. browser_type for typing.

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