Find package files in a game directory

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

No annotations are provided, so the description must carry the behavioral burden. It discloses that scanning is recursive, what file types are targeted, and that the tool is meant for discovery ('so you know what to pass'), implying a non-destructive operation. It doesn't detail edge cases like symlink handling or empty results, but for a file-listing tool this is reasonably transparent.

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 sentences with no filler. The first sentence packs the action, target, extensions, and purpose; the second gives a clear user-interaction instruction. Information is front-loaded and every part earns its place.

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?

Given the tool has 4 parameters, no annotations, and no output schema, the description covers the essential aspects: what it does, why it's used, and the interaction requirement. It doesn't mention return format or explicitly contrast with siblings, but the purpose is clear enough for an agent to select and invoke it correctly.

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%, so the baseline is 3. The description adds a bit of value by giving concrete extension examples and emphasizing that the directory should come from the user, but it doesn't deepen parameter semantics beyond the schema descriptions.

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 states a specific action ('Recursively scan a directory') with a clear resource ('Unreal package files') and example extensions. It also explains the downstream purpose ('so you know what to pass to other tools'), which distinguishes it from sibling tools like umodel_list_objects (lists objects inside packages) and pak_list (lists contents of archives).

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 explicitly instructs the agent to ask the user for the game directory before scanning, providing a clear prerequisite. It also frames the tool as a discovery/feed step for other tools, which implies when to use it (before export/extract operations). However, it doesn't explicitly mention alternatives or negations, so it's not a perfect 5.

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