browser_init

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

With no annotations, the description carries the full burden and does add some behavioral context: it mentions automatic recovery of stale sessions and exposes anti-detection/WebRTC protections. But it does not disclose consequences such as browser process lifetime, resource consumption, or the need to later call browser_close.

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?

Two sentences with no filler: the first states the core action and enumerates capabilities, the second adds an important recovery behavior. The most important verb ('Initialize') is front-loaded.

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 9-parameter tool with no output schema and no annotations, the description is too thin: it never states what the tool returns or how the agent knows initialization succeeded. It also omits setup details like proxy formatting or how contextOptions interact with defaults, leaving the agent to infer success criteria.

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 documentation already covers 7 of 9 parameters, and the description adds useful semantic grouping (e.g., 'biometric anti-detection hardware spoofing (WebGL, Canvas, AudioContext)' for spoofFingerprint, 'resource filtering' for enableBlocker, 'WebRTC leak protection' for blockWebRTCLeaks). This goes beyond the bare schema labels without being redundant.

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 opens with the specific verb 'Initialize' and a clear resource ('a browser session'), and the enumerated configuration options make its scope explicit. Among sibling tools like navigate, browser_close, and wait, this is unambiguously the session-start tool.

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 implies it should be used to start a browser session but never states when to call it, such as before navigation actions, or when not to use it. It also does not mention alternatives or warn against re-initializing an existing session, beyond the vague recovery behavior.

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