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

With no annotations provided, the description carries the full behavioral burden and does so thoroughly. It discloses verification by re-reading scopes, before/after count reporting, platform-specific cookie-removal mechanisms, HTTP cache limitations on iOS, and the fact that Basic-auth credentials are not cleared.

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 long, but front-loaded with the core purpose and use case, and nearly every sentence carries operational value. A small amount of trimming is possible, such as the specific QA environment verification detail, but overall the density is justified by the tool's platform-specific complexity.

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 tool with no annotations and no output schema, the description is remarkably complete. It covers platform differences, verification behavior, limitations, Basic-auth caveats, and a remediation path, so an agent has everything needed to invoke it correctly and interpret its results.

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 coverage is 100%, so the baseline is 3, but the description adds real parameter-level meaning: it explains the 'cache' scope is handled differently per platform, that unsupported scopes are reported rather than silently skipped, and clarifies the scope of 'all'. This goes beyond the enum definitions in the schema.

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?

States a specific verb and resource: clear cookies, localStorage, sessionStorage, and/or Cache Storage API for a page in the device browser. It also distinguishes itself from webpage_reload by explicitly noting that reload preserves localStorage, making the purpose and scope unmistakable.

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?

Explicitly says 'USE THIS to get a genuinely clean session between test cases' and contrasts it with webpage_reload's localStorage-preserving behavior. It also gives a concrete follow-up action for Basic-auth cases, so an agent knows when to choose this tool and what to do instead when it is insufficient.

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