Navigate browser page back

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

The description adds meaningful behavioral context beyond the annotations by stating that only the specified page is affected, and other roles' pages/sessions remain untouched. This is valuable because the tool is a navigation action that mutates history position but is scoped. It does not contradict the annotations and provides useful isolation semantics.

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 action, scope, and isolation guarantee without unnecessary filler. It is appropriately sized and front-loaded, making it easy for an agent to parse quickly.

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 simple nature, the presence of an output schema, and annotations, the description covers the essential behavior and scope. It does not cover edge cases such as behavior when there is no history, but that is likely acceptable for a low-complexity tool. The description is complete enough for basic invocation and role isolation.

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?

The input schema's parameter descriptions are absent (schema_description_coverage is 0%), so the description must compensate. It mentions page and session concepts indirectly, but it never explains the meaning of sessionId, pageId, or timeoutMs. The description alone is insufficient for an agent to know how to correctly populate the parameters.

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: 'Navigate backward in the history of one explicitly addressed page.' It uses a specific verb ('navigate backward') and resource ('history of a page'), and the phrase 'one explicitly addressed page' differentiates it from broader navigation or session-level tools. It is also distinct from sibling tools like browser_forward and browser_navigate.

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 gives useful context: the action applies to exactly one page and does not affect pages/sessions used by other roles. This clarifies the scope but does not explicitly state 'use this instead of browser_forward when...' or list exclusions. Thus context is clear, but explicit when/when-not alternatives are missing.

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