browser_open

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

Beyond the annotations (which already indicate a non-read, mutable action), the description adds critical behavioral details: it blocks certain protocols and hosts, and requires a lease_id. This informs the agent of restrictions and prerequisites without contradicting annotations.

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 concise sentences, front-loaded with the action. Every sentence provides critical information: what it does, what it blocks, and what it requires. No fluff or redundancy.

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 navigation tool with an output schema present and good annotations, the description covers the core function, constraints, and prerequisite. It is sufficiently complete for an agent to select and invoke it correctly among many sibling browser tools.

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?

With schema description coverage at 0%, the description compensates by constraining the URL parameter to loopback http(s) addresses and highlighting that lease_id is mandatory. It does not explain what lease_id is, but the requirement is stated, which adds value over the bare 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?

The description clearly states the tool navigates to a loopback http(s) URL, with specific verb ('Navigate') and resource (loopback URL). It distinguishes itself from siblings by explicitly blocking file:// and off-loopback hosts, making it unique among browser tools.

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 implies when to use this tool: for navigating to local development servers only. The constraints (blocks file:// and off-loopback hosts) give clear context, though it does not explicitly name alternative tools for other navigation scenarios.

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