browser_press_key

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

Annotations already declare destructiveHint=true and readOnlyHint=false, indicating this is a write operation that can change state. The description doesn't add behavioral context beyond this, such as what happens if no browser is open, whether it waits for page load, or if it has side effects like triggering events. It doesn't contradict annotations but adds minimal value beyond them.

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, clear sentence with zero wasted words. It's front-loaded with the core action and efficiently communicates the essential function without unnecessary elaboration. Every word earns its place, making it easy to parse quickly.

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 single-parameter tool with full schema coverage and annotations covering safety (destructive) and scope (openWorld), the description is minimally adequate. However, it lacks context about the browser environment, error conditions, or what constitutes valid key names beyond the schema examples. Without an output schema, it doesn't describe return values or success indicators.

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%, with the 'key' parameter fully documented in the schema as 'Name of the key to press or a character to generate'. The description adds no additional parameter semantics beyond what the schema provides, such as examples beyond ArrowLeft/a or special key combinations. Baseline 3 is appropriate given high 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 action ('Press') and target ('a key on the keyboard'), making the purpose immediately understandable. It distinguishes from siblings like browser_type (which types text) and browser_click (which clicks mouse), though it doesn't explicitly mention these distinctions. The description is specific but could be more precise about scope.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when to choose browser_press_key over browser_type (for single keys vs text input) or browser_click (for mouse interactions), nor does it specify prerequisites like requiring an active browser session. Usage context is implied but not stated.

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