browser_launch

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

With no annotations, the description provides thorough behavioral details: headless default, immediate navigation with load event wait, automatic enabling of Accessibility, DOM, Performance domains, and Target.setAutoAttach. It also discloses the implicit recording conflict with autoTrackHistory. No annotations to contradict.

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 concise (4-5 sentences) with no redundant information. It front-loads core purpose and mandatory nature, then lists key behaviors and parameters efficiently. Every sentence contributes meaningful information.

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?

Given the tool's complexity (launch, CDP session, navigation, history recording), the description covers all essential aspects. It explains what happens after launch, default modes, parameter effects, and preset automations. No output schema is needed as return values are implied (session created). It is fully complete from an agent's perspective.

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 100%, so baseline is 3. The description adds value by stating defaults (headless true), explaining the implicit recording behavior for autoTrackHistory, and noting the default sessionHistoryDir path. This extra context justifies a 4.

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 clearly states the tool's action: 'Launch a Chromium browser instance and establish a CDP session.' It explicitly marks this as the mandatory first step, distinguishing it from other browser tools. The verb 'launch' is specific to the resource 'browser instance', and the mandatory nature sets clear context.

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 'This is the mandatory first step before any other tool can be used.' It provides guidance on headless mode vs visual debugging, URL navigation, and autoTrackHistory with a conflict warning. This fully addresses when and how to use the tool.

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