zen_focus

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It does not mention what happens if the element is not found, whether it scrolls to the element, or any side effects. This is insufficient for a tool that mutates focus state.

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 very short (5 words), which is concise but may be too terse. It lacks elaboration that would make it valuable, but it is not overly verbose. It earns its place but does not add much beyond the name.

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 lack of output schema and 0% parameter coverage, the description is incomplete. It does not explain return behavior, focus management, or how it interacts with the page. A more detailed description is needed for a tool with two parameters and no structural aids.

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 0%, and the description adds no meaning to the parameters. The 'selector' parameter is not explained (e.g., CSS syntax), and the optional 'tab_id' parameter lacks context for its purpose. The description fails to compensate for the lack of schema documentation.

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 action: move focus to the matched element. It uses a specific verb and resource. However, it does not differentiate from similar sibling tools like zen_focus_window (which focuses a window) or zen_blur (which removes focus), making it slightly less clear in context.

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?

No guidance is provided on when to use this tool versus alternatives, nor are there any prerequisites or exclusions mentioned. The description lacks context for appropriate usage.

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