Type text

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

The description discloses a key behavioral trait beyond the annotations: the default fast path uses Input.insertText without per-character key events, and it explicitly states when to use slowly:true. This is critical because many pages rely on per-key events, and the description surfaces this behavior so the agent can make an informed choice. The annotations (readOnlyHint: false, destructiveHint: false) already indicate it's a write operation, and the description adds valuable detail about how the write is performed.

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 two sentences long with no unnecessary filler. The first sentence states the core purpose, and the second immediately provides the key behavioral nuance. The information is front-loaded and each sentence earns its place. It is both concise and structured effectively for quick comprehension.

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 simple typing tool with a well-documented schema and annotations, the description covers the most important behavioral nuance (fast path vs. slow). It does not mention whether typing clears existing content or appends at the cursor, which could be a minor gap, but this is not critical for most use cases. Given the tool's simplicity and the schema/annotation coverage, the description is sufficiently 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 100%, so all parameters are documented. The description adds meaning beyond the schema by explaining the default behavior of the 'slowly' parameter (fast path vs. real per-key events) and when to override it. Other parameters like 'target' and 'text' are already well-described in the schema, and the description does not need to repeat them. The added context for 'slowly' justifies a score above the baseline of 3.

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 tool's purpose: 'Type text into an editable element.' The verb 'Type' and resource 'text into an editable element' are specific, and the description also mentions the fast path vs. slow path, which helps distinguish it from sibling tools like browser_press_key (single key presses) or browser_click (clicking). The purpose is unambiguous and directly ties to the tool's name.

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 a clear usage condition for the 'slowly' parameter ('use slowly:true only when the page needs real per-key events'), which is a form of usage guidance. However, it does not explicitly contrast this tool with alternatives like browser_fill_form or browser_press_key, nor does it state when not to use this tool. The context is clear enough that an agent would know to use it for typing, but explicit exclusions are missing.

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