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

No annotations are provided, so the description carries the burden. It discloses the behavior (history.back()) and cross-platform support, but does not mention edge cases like what happens if there is no history entry, whether it waits for navigation to complete, or whether it affects pageId/tab state. The mention of history.back() is a useful implementation detail.

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, focused sentence that front-loads the core action and platform support. No wasted words.

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 simple navigation action with a clear schema, the description is mostly complete. However, it lacks guidance on edge cases (e.g., no history, pageId behavior) and does not explain the relationship to similar sibling tools. Given the large sibling list, a bit more context would help.

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 schema, but the schema itself is clear. Baseline 3 is appropriate.

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 (navigate back one entry in session history), the mechanism (history.back()), and the platform scope (iOS Safari and Android Chrome). This distinguishes it from siblings like webpage_forward, web_back, and session_back by specifying the device browser context.

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 usage for device browser navigation but does not explicitly state when to prefer this over alternatives like web_back, session_back, or playwright_back. It mentions cross-platform support, which helps, but lacks explicit when-to-use or when-not-to-use guidance.

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