Navigate a browser page back one entry in its history to return to the previous page. Specify a page or session, or use the active page and session by default.
Go back one entry in the page history.
| Name | Required | Description | Default |
|---|---|---|---|
| pageId | No | Defaults to the active page | |
| sessionId | No | Defaults to the active session |
Changes observed during successful MCP inspections.
v2026.10.24Input schema / properties / pageId / descriptionPrevious value: -"Stable page ID; defaults to the session active page"New value: +"Defaults to the active page"Input schema / properties / sessionId / descriptionPrevious value: -"Optional session ID; defaults to this MCP client active session"New value: +"Defaults to the active session"v2026.8.14Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It discloses that exactly one history entry is traversed, but it does not explain what happens when there is no previous entry, whether navigation waits for page load, or any other side effect.
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 front-loaded sentence with no filler. It communicates the action directly and efficiently.
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 tool, the description is minimally sufficient alongside the fully described optional parameters. It still omits behavioral edge cases such as history-boundary behavior, which matters because no annotations or output schema provide that context.
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%, and both parameters are optional with clear schema descriptions. The description adds no parameter-level detail beyond the schema, so the baseline score of 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 states a specific verb and resource: 'Go back one entry in the page history.' This distinguishes it from sibling navigation tools such as nex_browser_go_forward and nex_browser_navigate without needing clarification.
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 usage is implied by the action: use it when the browser should return to the previous history entry. However, it does not explicitly state when to use it instead of nex_browser_go_forward, nex_browser_navigate, or nex_browser_reload.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.