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

With no annotations provided, the description carries full burden. It discloses critical behavioral traits: mode behaviors (mock vs. abort), scope (web content only, no device-wide changes, no certificate installation), persistence (routes survive navigation), and a platform caveat for iOS headers charset handling. Missing some potential edge cases (e.g., order of multiple routes, concurrency limits), but overall transparent enough for an agent to understand outcomes.

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 well-structured with multiple sentences that front-load the core action and mode explanation before detailing constraints and alternatives. Every sentence adds value, and it avoids fluff. Slightly longer than minimal, but all content is relevant and clearly ordered.

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 (14 parameters, no output schema, no annotations), the description covers the essential behavior, modes, scope, constraints, and even provides iOS-specific guidance. It doesn't explain regex pattern format or the exact behavior of updating an existing route (beyond 'update in place'), but combined with the schema descriptions, an agent should have enough context to use the tool correctly.

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 meaningful value beyond schema: explains default mode ('mock'), provides iOS caveat for headers parameter, recommends omitting pageId to follow the active page, and explains matchType default ('contains'). This extra context helps an agent choose correct parameter values.

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 adds or updates a mock/abort rule for browser requests on the device. It distinguishes two modes ('mock' serves a canned response, 'abort' fails the request) and explicitly limits scope to web content only, contrasting with native app mock tools (e.g., xxx_traffic_mock_add). This differentiates it from siblings like android_devtools_mock_add and ios_safari_mock_add, which are platform-specific variants.

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 provides explicit when-to-use guidance: it explains the two modes and their effects, states that routes apply immediately and survive navigation, and gives a clear alternative for native app requests: 'use android_traffic_mock_add / ios_traffic_mock_add instead.' It also advises on pageId usage ('recommended' to omit for automatic tracking). No ambiguity about when to use this tool versus alternatives.

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