Types keyboard text into a previously focused input on a specific browser page; optionally presses a submit key such as Enter or Tab.
Type text using keyboard into a previously focused input
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | The text to type | |
| pageId | Yes | Targets a specific page by ID. | |
| submitKey | No | Optional key to press after typing. E.g., "Enter", "Tab", "Escape" |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotation readOnlyHint=false establishes this as a mutating action, which the description does not contradict. The description adds one behavioral trait beyond the annotations: it simulates keyboard input into an element that must already have focus, implying prior interaction state. It does not disclose what happens on failure, timing, or whether the text is appended versus replacing existing content.
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 front-loaded sentence with no filler. Every clause — verb, mechanism, target precondition — carries 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?
For a simple 3-parameter, no-output-schema tool with a fully documented schema and an annotation covering the safety profile, the description covers the essentials. The only gap is the absence of explicit differentiation from fill, which the agent must infer from wording alone.
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 text, pageId, and submitKey are all documented in the schema itself. The description adds no syntax, format, or edge-case detail beyond what the schema provides, so the baseline 3 applies.
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?
States a specific verb ("Type text") and the mechanism ("using keyboard"), plus a scope constraint ("into a previously focused input") that distinguishes it from a value-setting tool like fill. It does not name the closest sibling (fill) to route the agent, so it stops short of 5.
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?
"Previously focused input" implies you must focus an element first (e.g. via click), which is useful implied guidance. But there is no explicit statement of when to use this versus fill/fill_form/press_key, all of which live in the sibling list.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.