Create Browser

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

With no annotations at all, the description still discloses the important behavioral facts: the browser is headless, it auto-expires, and it has a default and maximum lifetime. It also carries a useful negative constraint ('Do NOT pass cdp_url here'). It stops short of stating concurrency limits, whether creation is metered, or what a failure looks like, so not a 5.

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?

Action statement is front-loaded, then a tight bullet list where each line maps to a distinct return field and its correct use. No filler sentences, and the expiry caveat sits last where it belongs.

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?

There is no output schema, so the description correctly takes on the job of documenting browser_id, connect_command, connect_url, cdp_url, and live_view_url — including the crucial warning not to interchange the URLs. That makes it callable and consumable. It lacks only edge-case behavior such as limits or error conditions.

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 coverage is 100% for the single timeout_seconds parameter, and the description merely restates the default 1 hour / max 24 hours already written in the schema. Baseline 3 is appropriate — the schema does the work and the description adds no new parameter semantics.

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?

Opens with a specific verb+resource: 'Create a headless Chrome browser instance.' That is unambiguously distinct from the siblings list_browsers, delete_browser, and file-retrieval tools, so an agent can route correctly without opening the schema.

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?

Usage is implied by naming — create a browser when you need one — and the description gives good downstream guidance on which returned handle to use for which client (agent-browser vs Playwright vs user sharing). However, it never states when to reach for this tool versus an existing browser session, and gives no exclusions or preconditions for creation.

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