ff_download

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

No annotations are provided, so the description carries full burden. It discloses key behaviors: uses browser download manager, leverages tab's cookies/auth, waits for completion, returns local path, and requires a real Firefox with bridge add-on. This is sufficient for safe usage, though it omits error handling or rate limits.

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 with no redundancy. The critical action and context are front-loaded. Every clause adds value (download action, auth usage, completion wait, return value, operational requirement).

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 download tool with two straightforward parameters, no output schema, and no annotations, the description covers purpose, behavior, and prerequisites completely. The agent knows what to expect and what is needed (real Firefox, add-on).

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 0%, but the description adds minimal parameter meaning. 'url' is implied as the file URL from the verb 'download'. 'filename' is mentioned but not described (optional custom name). Without explicit param details, the description partially compensates but leaves some ambiguity.

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 tool downloads a file to disk via the browser's download manager, using the tab's cookies/auth for protected files. It distinguishes itself from siblings like ff_fetch (in-memory fetch) and ff_list_downloads (list downloads) by specifying real Firefox operation and return of local path.

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 provides clear context for when to use (downloading files requiring browser auth via download manager) and mentions a prerequisite (bridge add-on). However, it does not explicitly state when not to use or name alternatives, though distinctions from siblings are implied.

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