browser_open

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

With no annotations, the description carries full behavioral disclosure. It reveals persistence ('logins survive between runs'), default visibility ('Headed by default'), and return behavior ('returns the first snapshot'). This goes beyond the schema but does not mention tab reuse, error handling, or side effects on existing browser state.

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?

Three sentences, each adding distinct value. The primary action is front-loaded, followed by state persistence and headless behavior. No filler 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?

Given no output schema and two parameters, the description covers the essentials but leaves out how browser_open interacts with the existing tab(s), whether it opens a new tab or reuses the current one, and what happens on invalid URLs. Sibling tools like browser_tabs and browser_close make this surrounding context more relevant.

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 indirectly explains headless via 'Headed by default' and implies url means the address to open, but it never explicitly maps each parameter or provides format constraints. Some meaning is added, but not enough to fully overcome the absent schema descriptions.

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 clear verb and resource: 'Open a URL in the persistent application browser.' It also notes the return value ('returns the first snapshot'), which distinguishes it from navigation, typing, and clicking siblings.

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 provides useful context like 'Logins survive between runs' and 'Headed by default so the user can handle 2FA/captcha', implying when the headless parameter matters. However, it never explicitly says when to prefer browser_open over alternatives or when not to use it, leaving some inference to the agent.

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