Replace a field value in a browser session, optionally press Enter, and wait for a completion selector; typed text is not echoed in the tool result.
Replace a field value, optionally press Enter and wait for a completion selector. Typed text is never echoed in the tool result.
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | ||
| selector | Yes | ||
| wait_for | No | ||
| session_id | Yes | ||
| timeout_ms | No | ||
| press_enter | No |
Changes observed during successful MCP inspections.
v0.4.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations cover the safety profile (readOnly=false, destructive=false, openWorld=true, non-idempotent), so credit goes to added context: the description discloses that it REPLACES a field value rather than appending, and that typed text is never echoed in the result - a non-obvious behavior an agent must know to verify success. It omits timeout behavior and failure modes.
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?
Two sentences, front-loaded with the action, followed by the single most important behavioral caveat. No filler or restatement of structured fields.
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 six-parameter mutation tool with a nested object and no output schema, the description leaves timeout semantics, session lifecycle, and failure behavior unaddressed. What is present is accurate and useful, but an agent still has gaps in the nested wait_for state and timeout boundaries.
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 carry parameter meaning. It explains press_enter ('optionally press Enter') and wait_for ('wait for a completion selector'), covering roughly half of the six parameters, but timeout_ms, session_id, and the wait_for state enum are left entirely to the schema.
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 concrete verb and resource (types/replaces text into a field) plus two optional behaviors (press Enter, wait for a selector). It doesn't explicitly contrast itself with siblings like click or verify_page, but the action is specific enough that an agent can distinguish it.
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?
No when-to-use guidance, no prerequisites, and no mention of alternatives. The phrase 'optionally press Enter and wait for a completion selector' hints at usage patterns but never states the conditions under which this tool should be chosen over click or navigate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.