Open a URL

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

With no annotations, the description carries the full burden and usefully discloses tab behavior: it switches to an existing tab, reuses the current working tab, and only opens a new tab the first time. It does not cover failure behavior or permissions, but for an open-URL tool the key behavioral traits are present.

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 front-loaded with the core action and then adds the critical navigation behavior without unnecessary filler. Both sentences earn their place.

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 two-parameter tool with no output schema, the description provides enough behavioral context to call it correctly. The main remaining gap is lack of sibling-tool differentiation.

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 needs to compensate for parameter meaning. It explains new_tab:false clearly, but it does not explain URL format or fully document the default true behavior of new_tab.

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 states a specific verb and resource: opening a URL in Chrome/Brave. It clearly distinguishes itself from manual keyboard navigation, but it does not differentiate itself from sibling tools such as browser_navigate or open_url.

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?

It gives explicit usage guidance: always use this instead of Cmd+L/Cmd+T plus typing. It also explains the new_tab:false case, but it does not state when to use sibling browser navigation tools instead.

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