Storage usage report

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

Goes well beyond the readOnlyHint/idempotentHint annotations: discloses the 5-minute cache and that other clients' changes are invisible until expiry, that refresh=true bypasses it, that trash stats are always uncached (~2.5 s), that a first walk of a large drive can take minutes, that sizes are summed file sizes rather than quota, and that `complete` flags partial results.

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?

Dense but well front-loaded: the report contents come first, then cost/cache caveats, then the `complete` flag. It is a long single paragraph, but nearly every clause carries operational information rather than 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?

With no output schema and a 4-param read tool, the description compensates by describing what the report contains and calling out the `complete` partial-results flag, plus latency and cache behavior. An agent has everything needed to call and interpret it.

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 baseline is 3, but the description adds genuine meaning: it explains what `refresh` interacts with (the cached walk), frames `path` as a subtree root, and ties `olderThanDays` to the old-files section. It does not restate the top/path defaults already in 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?

States a specific verb+resource (storage analytics over a subtree) and enumerates the report contents: totals, largest files/folders, extension/media breakdown, old files, trash stats. This clearly separates it from siblings like drive_info, drive_tree, and drive_find_duplicates.

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?

Gives clear context for use (analytics on a subtree) and notes the trash-stats cost and cache staleness, but never explicitly names an alternative tool or a when-not-to-use condition. Implicit routing is strong, explicit routing is absent.

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