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

Annotations already declare it is a non-read-only, non-destructive, open-world write. The description adds genuinely new behavioral context beyond them: an 8-level nesting cap and the sibling-uniqueness constraint on names, both operationally important. It stops short of describing what happens on a duplicate-name or depth violation, leaving error behavior implicit.

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, front-loaded with the core action and followed by the two constraints an agent actually needs before calling. Nothing is redundant with the title or padding.

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 an output schema present, return values need no explanation, and the description covers the mutation's key guardrails (depth, uniqueness, naming). Only error/failure outcomes for violating those guardrails are left unstated, a minor residual gap for a two-parameter tool.

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 100%, so both parameters are already documented, which sets the baseline at 3. The description adds some value by stating the 8-level depth limit and the sibling-uniqueness rule, but it does not extend name syntax or parentId semantics beyond the schema's own text.

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?

Opens with a specific verb and resource ('Create a storage folder'), which is unambiguous against siblings like delete_folder or update_folder even without being named explicitly. It does not explicitly contrast with siblings such as move_file or upload_file, which keeps it just short of a 5.

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 parentId guidance ('pass parentId to nest... or omit it for a top-level folder') tells the agent how to use a parameter but not when to prefer this tool over alternatives or what prerequisites exist. Usage is implied by the create-vs-manage sibling set rather than stated.

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