browser_tab_new

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, covering safety and scope. The description adds minimal context ('new tab' implies creation, not modification of existing tabs), but doesn't detail behavioral aspects like whether it focuses the tab, handles errors for invalid URLs, or interacts with browser state beyond what annotations provide.

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 'Open a new tab' is a single, front-loaded sentence with zero waste. It efficiently conveys the core action without unnecessary words, making it highly concise and well-structured.

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 low complexity (one optional parameter), rich annotations (covering safety and scope), and no output schema, the description is mostly complete. However, it lacks context on usage scenarios or integration with sibling tools, leaving minor gaps for an AI agent to infer optimal use.

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%, with the parameter 'url' fully documented in the schema. The description doesn't add any semantic details beyond what's in the schema (e.g., URL format, default behavior). With high schema coverage, 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 'Open a new tab' is a specific verb+resource action that clearly distinguishes it from siblings like browser_tab_close (close), browser_tab_list (list), or browser_tab_select (select). It precisely states what the tool does without ambiguity.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an open browser), exclusions (e.g., not for opening windows), or comparisons to siblings like browser_navigate (which might reuse existing tabs).

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