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

Annotations already declare openWorldHint and destructiveHint=false, but the description adds genuinely new traits: navigation history semantics and that it 'does not submit page forms,' which is meaningful for an agent deciding between forward navigation and a form-triggering action.

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, no filler, with the primary action front-loaded and the precondition second. Nothing to cut.

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?

With an output schema and annotations present, the description covers the essentials. A minor gap is what happens at the end of history or on a page with no forward entry, but that is not required for correct invocation.

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?

Seven parameters with 100% schema description coverage, including how device, target_id, title, and url_contains select the tab. The description adds nothing about parameters, so the schema carries the load — baseline 3.

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+resource+scope: 'move forward one step in the history of a selected Chromium tab.' The mention of 'a previous backward navigation' implicitly distinguishes it from browser_back, though it never names the sibling outright.

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?

Gives an implied precondition ('requires a previous backward navigation'), which tells the agent when the tool is valid, but never states when to avoid it or names browser_back/browser_navigate_url as alternatives.

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