open_browser

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

No annotations are provided, so the description must disclose behavioral traits. It only hints that the tool should be called once but does not explain what happens if called multiple times, whether it is idempotent, or any side effects. The absence of such details leaves significant behavioral ambiguity.

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 exceptionally concise: two short sentences that immediately state the primary action and add a usage note. Every word earns its place, with no wasted text.

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?

Even though the tool is simple, the description is incomplete because it fails to explain the 'headless' parameter and does not clarify the consequences of repeated calls. The lack of annotations makes this incompleteness more impactful, leaving essential context 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?

The input schema includes a 'headless' parameter with a default of true, but the description does not mention it at all. With 0% schema description coverage, the agent receives no explanation of what 'headless' means or when to set it, making this a major gap.

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 action: 'Launch the Chromium browser.' This is a specific verb+resource pair that distinguishes it from siblings like navigate or close_browser. The additional clause 'Call this once before navigating anywhere' further clarifies its role as the initial setup step.

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 gives explicit timing guidance: 'Call this once before navigating anywhere,' which tells the agent when to use it. It does not mention when-not-to-use or alternatives, but no direct alternative exists among the siblings, so the guidance is clear enough for a 4.

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