Open browser tab

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

The description adds value beyond annotations: it states tab reuse behavior and mentions the new_tab parameter's effect. Annotations already indicate destructiveHint=true and openWorldHint=true, so the agent knows this modifies state. The description doesn't contradict annotations. However, it could clarify that opening a URL may replace the current page in the active tab.

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 sentence that conveys the core behavior efficiently. It could be split for clarity but is not wasteful. No fluff.

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 an output schema exists (so return values are documented), annotations cover mutation and open-world hints, the description is sufficient for a navigation tool. It covers the main behavioral nuance (tab reuse), though could mention the browser may close existing tabs if headless changes mode.

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?

With 67% schema description coverage, the description adds minimal meaning beyond the schema. It explains the new_tab parameter's role but doesn't elaborate on url (already clear from schema) or headless (which has detailed schema descriptions). 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 tool opens or navigates an MCP tab, specifying it reuses the active tab unless new_tab is true. This distinguishes it from siblings like browser_status or browser_close.

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 when to use new_tab (true for a new tab), but does not explicitly guide when to use this tool versus alternatives like scraper tools for page content extraction, or browser_status for checking state. No when-not-to-use guidance is provided.

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