Replaces the content of a web page's editable element by index with specified text, optionally pressing Enter to submit. Returns updated page snapshot for verification.
Type text into editable element [index] (replaces its content). Set submit=true to press Enter afterwards. Returns the new snapshot.
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | ||
| index | Yes | ||
| submit | No | Press Enter after typing |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations present, the description carries the behavioral burden. It discloses three meaningful behaviors: content replacement, optional Enter submission, and returning a new snapshot. It omits edge-case behaviors like invalid index handling or whether the element must be visible, but the disclosed behaviors are substantive for a simple tool.
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 compact and front-loaded: the main action appears first, followed by the optional submit behavior and return value. Every clause earns its place with no filler or repeated schema content.
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 three-parameter tool with no output schema, the description covers the core action, replacement semantics, optional submission, and return snapshot. Minor gaps such as behavior on invalid indexes or focus requirements keep it from being fully complete, but nothing essential for a normal call is missing.
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 only 33%, so the description needs to compensate. It gives useful context for index ('editable element [index]') and text ('Type text'), and restates the submit behavior. However, it adds little beyond the schema's own submit description and does not clarify index format, zero-based indexing, or text handling details.
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 clear verb+resource pair ('Type text into editable element [index]') and distinguishes itself from siblings like press_key by targeting an element and typing text rather than simulating a key press. The parenthetical 'replaces its content' further sharpens the tool's exact behavior.
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 implies this is for entering text into an editable element, but it never explicitly says when to use this tool versus alternatives such as press_key or click. No exclusions or conditional routing are provided, so the agent must infer the appropriate context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.