browser.fork_session

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

Annotations already indicate non-destructive behavior (destructiveHint=false). The description adds that it creates an 'independent' session, clarifying no interference with the original. However, it doesn't disclose any potential side effects or limitations beyond the snapshot, which is acceptable given the annotations.

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: first defines the action with clear steps, second adds the use case. No redundant or extraneous information. Every sentence contributes meaning.

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 core functionality but omits parameter details and return behavior (no output schema). For a tool with 3 parameters and moderate complexity, it leaves gaps in clarity, especially for optional parameters. The annotations help somewhat, but the description could elaborate on parameter semantics.

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?

The input schema has 3 parameters (session_id, name, start_url) with 0% description coverage. The tool description does not explicitly describe these parameters. While 'session_id' is implied by 'snapshot its... current URL', the 'name' and 'start_url' parameters lack any explanation of their purpose, making it harder for the agent to use correctly.

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 action: 'Fork a session: snapshot its cookies, storage state, and current URL, then create a new independent session with that state.' This distinguishes it from siblings like 'create_session' (new blank session) and 'close_session' (destroy session). The verb is specific and the resource is well-defined.

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 includes 'Useful for branching workflows or running parallel variants,' providing clear context for when to use this tool. While it doesn't explicitly mention alternatives, the use case is well-implied and distinct from other session operations.

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