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

Adds substantial context beyond the annotations: state persists across calls (cookies/login survive), it is free, sign is governed by colony standing, and it returns a specific capacity error shape with a remediation hint to close sessions. Annotations only convey the non-read-only, non-idempotent, non-destructive profile.

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?

Front-loaded with the core purpose and the return value, then behavioral detail. Dense but each clause carries information; caps and em-dashes add emphasis rather than noise, though it is slightly packed for a single paragraph.

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?

No output schema, but the description covers the key return (browser_id), the failure mode (at-capacity error), the free/governance constraints, and the lifecycle guidance to close sessions. Nothing needed to call it correctly is missing.

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%, so the baseline is 3, but the description adds real meaning for sign (Web Bot Auth signed identity governed by colony standing) and the capacity behavior. It does not extend semantics for proxy/handle/account, which stay schema-only.

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?

States a specific verb+resource: opens a PERSISTENT browser session and returns a browser_id to drive. It explicitly names the sibling tools that consume that id (browse_navigate/snapshot/click/type/fill/close) and contrasts with the read-only page tools, so an agent can place it instantly.

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?

Gives clear context for when to use it ('log in, fill forms, click through multi-page flows') and an implicit exclusion ('not just read one page'), plus the instruction to close finished sessions. It stops just short of naming the specific read alternative (browse_read/web_read) by name.

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