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

Beyond the mutation implied by readOnlyHint=false, the description adds the key behavioral invariant that Foundry maintains separate folder trees per document type, and it defines parentId's nesting/root semantics. It doesn't describe return value or failure modes, but annotations already signal non-read-only behavior, lowering the burden.

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?

Two sentences: the first states the core action and object; the second explains the two contextual behaviors that matter for correct invocation. 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?

Given six parameters fully described in the schema and no nested objects, the description supplies the missing system-level context (type separation, nesting, root omission) needed to call the tool confidently. The only notable omission is the response/return behavior, which is not covered because no output schema exists, but the call itself is fully specified.

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 all six parameters. The description adds non-redundant meaning for type (separate tree per type) and parentId (nests inside another folder; omit for root), helping the agent map those fields correctly.

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 precise action – 'Create a folder of the given document type' – and differentiates from sibling folder-delete/get/list/update by naming the creation operation. The per-type folder-tree note further clarifies what a folder creation means in Foundry.

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 makes the invocation context clear: use when creating a new folder of a known document type, including the root-vs-nested choice via parentId. It does not explicitly name alternatives like folder-update, but no competing create tool exists among siblings, so the lack of exclusion is not a real gap.

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