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fill_by_uid

Fill a text input or textarea using its UID from a snapshot, enabling precise form value during browser automation testing.

Instructions

Fill text input/textarea by UID.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
uidYesInput element UID from snapshot
valueYesText to fill

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed2 schema fields changedv1.0.0
    • changedInput schema / properties / uid / description
      Previous value: -"The UID of the input element"New value: +"Input element UID from snapshot"
    • changedInput schema / properties / value / description
      Previous value: -"The text value to fill into the input"New value: +"Text to fill"
  2. First observed

TDQS

C2.9/5.0
Behavior2/5

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

Annotations indicate it's not read-only, consistent with fill. But no additional disclosure about behavior: e.g., whether it clears existing value, what happens if element is not found, or if it supports only text inputs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness2/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Too brief (6 words) and leaves out critical details. Not earning its place; under-specification.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema, so description should explain return behavior (success/failure). It does not. Also missing context about element type constraints.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with descriptions for both parameters. Description adds no extra meaning beyond schema, so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the action (fill) and the resource (text input/textarea by UID). It distinguishes from sibling tools like click_by_uid, hover_by_uid, and fill_form_by_uid.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool over alternatives, such as fill_form_by_uid or upload_file_by_uid. No exclusions or prerequisites.

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

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