b2_list_largest_files

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

Annotations already mark the tool as read-only and idempotent. The description adds non-obvious behavior beyond that: the scan is bounded by max_scan and a time budget, results may come back as truncated=true, and the tool returns only name/size/upload time, never contents. This is excellent disclosure of live-listing behavior.

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?

Four sentences with a clear progression: purpose, intended queries, caveat and workaround, return contract. Every sentence adds useful information and there is no filler or restatement of the tool name.

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 read-only listing tool with fully documented parameters and annotations covering safety, the description supplies the missing output details (name, size, upload time, never contents) and the truncation caveat. An agent has everything needed to select and invoke the tool 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 meaning by noting bucket accepts a name or bucketId, explaining that prefix can focus on a subtree for a complete ranking, and tying max_scan to the truncation behavior. Only the limit parameter is left entirely to the 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 opens with a specific verb and resource: 'List a bucket's largest objects by size'. It also gives natural-language triggers ('largest files', 'what's taking up space') and closes with a clear boundary ('never contents'), so an agent can distinguish this from listing buckets or fetching object content.

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 gives clear contexts for use, including quoted user intents, and provides a prefix-based strategy for large buckets. It does not explicitly name a sibling alternative or state when not to use it, but no close sibling exists for this capability, so the guidance is strong.

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