browser_open

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

No annotations are provided, so the description carries the full burden — and it excels. It discloses session persistence across runs, cookie-deletion risk from concurrent drivers, the browser_busy return with holder's name, and the constraint that the session cannot be rebuilt. These are non-obvious behaviors an agent could not infer from the schema.

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?

Purpose is front-loaded in the first sentence, and every subsequent sentence earns its place by conveying a distinct operational fact: persistence, contention, cookie destruction, busy signal, and retry guidance. There is no redundancy or filler.

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 one-parameter tool with an output schema (which likely documents return values), the description covers purpose, session behavior, contention, and the failure mode. Minor gaps remain — e.g., what constitutes a successful open or whether the tool waits for page load — but the non-obvious operational facts are all present.

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 must compensate. It maps the single url parameter to 'a URL... in the automation browser,' which defines it adequately. However, it adds no format, scheme, or validation detail beyond what the schema's own property name 'url' already implies.

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 opening sentence 'Open a URL in the automation browser' states a specific verb, resource, and target. This is clearly distinct from siblings like browser_tabs, browser_screenshot, browser_scroll, and browser_close, so an agent can tell them apart without opening schemas.

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?

Provides strong operational guidance: the persistent-profile model, the single-driver constraint, the browser_busy failure signal, and explicit 'do not retry in a loop' advice. It does not explicitly name sibling alternatives or when-not conditions, but the context for correct use is clearly established.

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