tab_close

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

With no annotations, the description carries the full burden. It discloses the operation is irreversible ('cannot be undone through this API') and notes a refusal condition ('refuses when no tab is marked active'). It also hints at output behavior ('Names the tab it is about to close'), though return format is unspecified. This is strong coverage for a destructive action, but not exhaustive.

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, zero filler. The primary action is front-loaded, and the critical caveat about irreversibility is placed immediately after. Every clause contributes value, making it efficient and easily scanable.

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 tool with one optional parameter and no output schema, the description covers purpose, destructive nature, parameter usage, and a prerequisite (tab_list). It does not specify the return value verbatim, but 'Names the tab' implies some output. Given the low complexity, this is largely complete; only a minor gap exists regarding the exact response format.

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?

The schema already explains expect_title thoroughly (must match to close, use tab_list); the description adds the strategic context 'pass expect_title when it matters which one goes,' which complements the schema by tying the parameter to a decision point. Since schema coverage is 100% and description adds meaningful guidance, this exceeds the baseline of 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 action ('Close') on a specific resource ('currently active chart tab'), clearly distinguishing it from sibling tab tools like tab_new, tab_switch, and tab_list. It also adds behavioral detail about refusing when no tab is active, which further clarifies intent.

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?

Provides clear usage context: tells the agent to use tab_list first to see titles and to pass expect_title when it matters which tab closes. However, it does not explicitly contrast with alternatives (e.g., 'use this instead of tab_switch'), so it lacks explicit when-not guidance.

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