Mock network requests

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

Annotations indicate readOnlyHint=false and destructiveHint=false, so the description adds context by stating it stubs responses and that mocking can be restarted by re-adding. It does not contradict annotations, but it does not disclose details like scope, persistence, or interactions with existing routes. The added 're-adding' note is useful but limited.

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 primary action is front-loaded, and the second sentence provides a useful behavioral note. Every word earns its place.

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?

While the core function is clear, the description lacks context about how this tool relates to other routing tools (e.g., browser_unroute, browser_route_list) and the lifecycle of the mock (e.g., does it persist across navigations? What happens on duplicate patterns?). An agent would need to infer these details from sibling names, which is not ideal. The description is incomplete for safe and correct usage.

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 all parameters (body, status, headers, pattern, contentType) are already documented in the schema. The description adds no additional parameter-specific information, so the baseline of 3 applies.

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 function: 'Stub responses for URLs matching a pattern.' It uses a specific verb (stub) and resource (responses for URLs), distinguishing it from related tools like browser_route_list and browser_unroute. The purpose is 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?

The description implies when to use it (when you need to mock network requests) but does not explicitly compare it to alternatives or state when not to use it. It mentions 'Restart mocking by re-adding the route,' which hints at a lifecycle but lacks explicit guidance on selecting this tool over siblings like browser_unroute or browser_route_list.

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