arc_close_tab

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

No annotations provided, so the description must fully disclose behavior. It only says 'close' with no mention of side effects (e.g., whether tab is closed silently, what happens if the tab doesn't exist, or if the window auto-closes). This is insufficient for a destructive 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?

The description is a single short sentence with no extraneous words. It is appropriately concise but could benefit from slightly more detail about parameter interaction.

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 close operation with well-described parameters, the description is minimally adequate. However, it lacks information about parameter precedence and post-close behavior, which would improve completeness.

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% with descriptions for both parameters (tab_index with 1-based index, url as partial match). The description adds no additional semantics beyond what the schema already provides, meeting the baseline.

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 it closes a tab ('指定したタブを閉じる'), which is specific to closing, distinguishing it from switching or duplicating tabs. However, it does not indicate that closing can be done by tab index or URL.

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 on when to use this tool versus siblings like arc_close_window, what to do if both parameters are provided, or prerequisites. The description offers no context about appropriate usage scenarios.

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