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

With no annotations provided, the description carries the full behavioral burden. It discloses the most important lifecycle behavior: repeated calls close the previous session. It also notes ownership by the API key user Pomu. It omits return value and error conditions, but the disclosed behaviors are material for safe invocation.

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 two concise sentences with the core action front-loaded. The second sentence efficiently adds navigation and replacement behavior without any 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?

The description covers the critical lifecycle behavior (creation, initial navigation, replacement) but does not address the 5 proxy-related parameters or the reuse contextId. With no output schema, the return value is also unspecified, leaving an agent with only partial information for invocation.

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 only 29% (only url and contextId have descriptions). The description only restates the url behavior already present in the schema ('可带初始 URL 直接导航') without adding new meaning. It provides no guidance for contextId or any of the proxy parameters, so it fails to compensate for the low schema coverage.

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 uses a specific verb ('创建'/create) and resource ('云浏览器会话'/cloud browser session), with an ownership qualifier. It also distinguishes itself from all sibling tools, which operate on an existing session (click, fill, navigate, etc.), making its function unambiguous.

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?

It clearly says the tool creates a new session, can navigate to an initial URL, and that repeated calls replace the current session (old session auto-closes). This gives clear context for when to call it, but it does not explicitly mention alternatives like using bf_navigate for later navigation.

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