start_browser

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

With no annotations, the description carries the behavioral burden. It adds useful context like the ordering requirement and headless-mode caveats, but it does not disclose what happens if called twice, whether a session is reused, or what cleanup is required.

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 short, front-loaded with the most important fact, and the Args section is cleanly structured. Every sentence adds value without fluff.

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 tool with 7 parameters and no annotations, the description is incomplete: three parameters are undocumented and session lifecycle behavior is not covered. The output schema covers return values, but the missing parameter semantics leave a significant gap.

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 gives meaningful semantics for headless, browser, uc, and incognito, but omits proxy, ad_block, and guest_mode entirely. This is partial compensation, not full.

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: 'Start a new browser session.' This clearly distinguishes it from sibling tools like close_browser, navigate, and refresh_page, and it is not a tautology of the tool name.

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 explicitly says 'Must be called before any other tool,' which gives clear when-to-use guidance. It does not discuss when not to use it or alternatives, but there is no real alternative for starting a browser session among the siblings.

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