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

With no annotations provided, the description carries the full behavioral burden. It clearly states the underlying action (history.forward()) and its effect, but it does not mention what happens when there is no forward history, whether a loaded page is required, or whether the call returns a result. These are notable gaps for an unannotated tool.

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 a single well-structured sentence that states the operation, the underlying API, and the platform support with no filler. The most important scoping detail, 'device browser', is front-loaded.

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 low-complexity navigation action, the description plus the fully documented schema is sufficient to invoke the tool. It covers what the tool does and on which platforms. Minor omissions like output behavior and no-op semantics keep it from being fully complete.

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 the schema already documents all four parameters. The description adds no parameter-specific meaning beyond the 'device browser' context, which matches the baseline of 3 for high schema coverage.

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 uses a specific verb and resource: 'Navigate the device browser forward one entry in its session history (history.forward())'. It also names the exact supported environments, iOS Safari and Android Chrome, which separates it from desktop-oriented navigation tools like web_forward or playwright_forward.

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 the tool is for device-based browser sessions by saying 'device browser' and 'works on BOTH iOS Safari and Android Chrome.' However, it never explicitly says when to prefer this over siblings like web_forward, playwright_forward, or webpage_back, so the usage context is inferred rather than stated.

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