firefox_close_tab

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

The description fails to disclose any behavioral traits. It does not indicate that closing a tab is destructive (irreversible), what happens if the sessionTabId is invalid, or any side effects. With no annotations, the description carries the full burden and is insufficient.

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 concise sentence with no unnecessary words. It is appropriately front-loaded and efficient.

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 like closing a tab, the description is minimally adequate. However, it lacks contextual information such as how to obtain the sessionTabId (e.g., from firefox_list_tabs) or that the action is irreversible. Given no output schema, more context about return behavior would help.

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%, so the baseline is 3. The tool description adds no meaning beyond the schema, which already describes sessionTabId. The schema description has a typo ('fire-fodex'), but the tool description does not correct or elaborate.

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 (close) and resource (Firefox tab), which distinguishes it from siblings like firefox_open_tab. However, it does not mention that it closes a specific tab identified by sessionTabId, missing an opportunity to clarify the target.

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 (e.g., firefox_release or navigating away). There is no mention of prerequisites, such as having a valid sessionTabId or ensuring the tab exists.

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