backup_storage_ranking

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

With no annotations, the description carries the full behavioral burden and succeeds: it marks the tool [READ], explains charge attribution, distinguishes ownerlessStoredBytes from unmatchedOwnerStoredBytes, warns about truncated results, and gives a billing judgment rule. This is unusually rich disclosure for a read operation.

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 long but appropriately sized for a complex ranking tool with no output schema or annotations. The core purpose is front-loaded, and each subsequent sentence adds required semantic nuance or a caveat rather than repeating the name or schema.

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 absence of annotations, output schema, and schema descriptions, the description is complete: it covers purpose, attribution rules, truncation caveats, version requirements, and all parameters. An agent has enough information to invoke and interpret 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 description coverage is 0%, so the description must compensate fully. It documents each of the three parameters with meaning, ranges, defaults, and usage guidance (raise max_backups for full coverage; omit target for default), exceeding what the bare schema provides.

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 verb and resource: objects ranked by backup storage consumed, largest first, and frames the exact question it answers. This distinguishes it from generic list or usage tools in the sibling set.

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?

It gives clear context for when to use the tool—answering which machines are most expensive to protect—and adds a version requirement (VBR 12.3+). However, it does not explicitly name alternatives or say when not to use it versus siblings like backup_object_storage_usage or repository_capacity_rca.

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