browser_navigate_back

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

No annotations exist, so the description carries the full burden. It does add one genuinely valuable behavioral fact — that the returned title and URL are untrusted page content — but omits the failure mode when there is no prior history entry, whether the page reloads, and whether navigation is blocking.

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?

Two sentences, zero filler, with the action stated first and the security caveat second. Nothing is wasted.

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 two-optional-parameter navigation tool with no output schema, the description covers purpose and return-value trust level. The main remaining gap is error behavior on an empty history stack, which matters for an agent deciding whether to call it speculatively.

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%: tabId's provenance ('from browser_tabs') and the backend enum values are already documented in the schema. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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 effect ('Go back one entry in the tab history'), which cleanly separates it from browser_navigate (goto URL) and browser_tabs. It never names a sibling explicitly, but the operation is unambiguous.

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 when-to-use case is strongly implied by 'go back one entry', but there is no explicit guidance on alternatives (e.g. use browser_navigate to go forward or to a specific URL) or on what to do when history is empty.

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