start_browser

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

With no annotations, the description carries the behavioral disclosure burden. It does well by explaining that the session uses CDP rather than WebDriver, that it is stealth-oriented, and that it must precede all other tools. It could go slightly further by noting lifecycle behavior such as whether repeated calls reset or reuse an existing session, but the core behavior is transparent.

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 tightly structured: a front-loaded purpose sentence, a key ordering constraint, a brief mode rationale, and a compact argument list. Every sentence earns its place, with no filler or repetition of schema defaults.

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 startup tool with six optional parameters and no annotations, the description covers the essential operational context: what the tool does, when to call it, and what each option controls. The presence of an output schema reduces the need to explain return values. A small gap is lack of guidance on calling start_browser again while a session already exists.

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 does: every parameter gets a meaningful, non-redundant explanation, including the proxy format example and the effect of headless/incognito/guest/ad_block. This gives the agent enough semantic detail to set options correctly.

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 action ('Launch') and the specific resource ('a Pure CDP Mode browser session'), making the tool's purpose unmistakable. It also distinguishes this setup tool from the many browser-action siblings by emphasizing CDP mode and mandatory first-use.

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?

'Must be called before any other tool' is an explicit and unambiguous usage requirement. The description also explains why this mode is preferable (stealth/bot-detection resistance), giving the agent clear context for selecting this tool first.

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