ff_screenshot

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

No annotations are provided, so the description carries the full burden. It discloses that it captures the visible area (not full page) and requires the add-on, but does not mention side effects, output format details, or error conditions.

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 two concise sentences with no redundant words. It is front-loaded with the primary action and format, followed by the prerequisite.

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 screenshot tool with one parameter and no output schema, the description provides essential context: output format (PNG), scope (visible area), and prerequisite. Could mention whether the output is returned as base64 or binary, but overall sufficient.

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 input schema has one parameter (tabId) with 0% description coverage. The description does not explain what tabId refers to (e.g., from ff_list_tabs) or how to obtain it, leaving ambiguity for the agent.

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: screenshot the visible area of a real tab in PNG format. It distinguishes itself from generic sibling tools like 'screenshot' by specifying it operates on a real Firefox tab and requires the bridge add-on.

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 includes a prerequisite (bridge add-on needed) and implies it's for real Firefox tabs. However, it does not explicitly state when to use this tool over alternatives like 'screenshot' or other ff_* tools.

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