list_files

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

With no annotations provided, the description carries the full burden and does well. It explicitly marks the tool as a read operation with '[read]', lists return fields (name, size, duration, labels, in_feed), and mentions all filters. This fully informs the agent of the tool's behavior and output.

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 sentence, front-loaded with the read indicator and core action. Every piece of information earns its place: operation type, resource, filters with examples, and return fields. No filler.

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 output schema exists, the description does not need to detail return values further. It covers filters, operation type, and a general resource overview. I deduct 1 point because the 'limit' parameter is not explained, though its default is visible in the schema; with 0% schema coverage, a brief mention would make it fully complete.

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 0%, so the description must compensate. It does so by explaining that 'query' is a substring for name/label, 'service' is exemplified with 'youtube', and 'label' is a filter. 'limit' is not mentioned explicitly but has a default visible in schema, and its purpose is inferable. The description adds substantial meaning beyond the raw schema.

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 'List downloaded files in vdl' with a specific verb and resource. It also lists optional filters (query, service, label) and return fields, distinguishing it from sibling tools like get_transcript or download.

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 says 'Optional filters' and lists them, giving clear context for when to use each filter. However, it does not explicitly mention when not to use this tool versus alternatives, though the read nature and filters are clear enough for an agent.

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