arachne_browser_run

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

With no annotations provided, the description must fully disclose behavior. It mentions browser actions but omits important details: whether a new browser instance is opened, if state persists (cookies/sessions), error handling, timeouts, or if the browser runs headlessly. The description is too brief to enable reliable agent decision-making.

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 very concise (one sentence and a fragment), but it sacrifices critical information. For a tool with nested parameters and no output schema, this brevity is insufficient. A slightly longer description that covers return values and behavioral notes would be more appropriate.

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?

Given the complexity (nested actions array, no output schema), the description is incomplete. It fails to explain what the tool returns (e.g., screenshots, extracted data, success status) or how errors are reported. The agent lacks sufficient context to understand the tool's full output and behavior.

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 the baseline is 3. The description lists actions (click, type, navigate, screenshot) which overlap with the schema's 'type' enum, adding no new meaning. It does not explain the actions array structure or how selectors and values are used, leaving the schema to carry the full burden.

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 function: 'Execute actions in a real browser: click, type, navigate, screenshot.' It specifies concrete actions and a typical use case ('For login flows, multi-page forms'), distinguishing it from siblings like arachne_browser_extract which likely focuses on data extraction.

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 phrase 'For login flows, multi-page forms' provides clear context for when to use this tool. However, it does not explicitly state when not to use it or mention alternatives, such as arachne_browser_extract for data extraction scenarios.

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