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

With no annotations, the description carries the behavioral burden and does well: it discloses that no bucket bytes are created, folders are drive_objects rows with kind=folder, root semantics, and the Archive refusal constraint for non-empty folders. This goes beyond a simple 'create' statement and surfaces the most important operational caveat.

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?

Three short sentences, each earning its place: the core operation and scope, the data-model/root semantics, and the critical prerequisite/alias. Information is front-loaded and there is 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?

For a simple metadata-only creation tool with 3 params, full schema coverage, and an output schema, the description covers the operation, data model, root behavior, and a key failure condition. Nothing essential is missing for an agent to call this 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 schema already documents title and parent_id. The description adds useful context for parent_id by explaining 'Root is parent_id IS NULL', but it does not add substantial meaning beyond the schema's own descriptions. Baseline 3 is appropriate.

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 and resource: 'Create a Storage folder', and immediately distinguishes it from byte-level operations with '(metadata only; no bucket bytes)'. It also names the deprecated alias drive_folder_create, making the tool's scope unambiguous relative to storage_* siblings.

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?

Provides clear context: this creates metadata-only folder rows, root is parent_id IS NULL, and Archive requires emptying active children first. It does not explicitly enumerate when-not-to-use scenarios versus storage_attach or file_create, but the metadata-only qualifier and folder-specific model make the intended use clear.

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