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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and the description adds real context beyond them: no duplicate-name checking (which explains the non-idempotent hint), the required edit access on the parent, and an explicit 'additive: nothing existing changes' guarantee that reinforces destructiveHint=false.

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?

Front-loaded with the core action and then the optional parent behavior, followed by duplicate-handling, return value, follow-up tools, and permissions. Every sentence carries a distinct operational fact with 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?

No output schema exists, but the description covers the return shape (folder_id and url), the permission prerequisite, duplicate behavior, and the hand-off tools for populating the folder. For a 3-parameter creation tool, nothing an agent needs to call it correctly is missing.

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 baseline is 3, but the description adds genuine meaning about parent_folder_id (optional, omit for root, values come from contents or search results) and names the returned folder_id. team_id and title semantics remain schema-only, so it stops short of a 5.

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 ('Create a folder') and immediately clarifies the nesting model, distinguishing it from sibling tools like contents, items_update, and the upload tools. An agent can tell what this does and how it relates to siblings without opening any schema.

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?

Explicitly routes the agent: call contents first if the folder may already exist (duplicates allowed), and use items_update or the upload tools to put assets inside the new folder. It also names when parent_folder_id should be omitted (root) versus supplied (nested), leaving nothing to inference.

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