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

Annotations declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false; the description reinforces non-idempotent behavior by emphasizing 'NEW' and duplicate-avoidance workflow. It adds nesting semantics and the root-level condition, though it does not mention permissions or failure modes.

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?

Four sentences, all purposeful and ordered from decision logic to parameter guidance to return value. Slightly verbose in re-explaining the parentFolderId workflow that the schema also covers.

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?

An output schema exists, so return values need not be detailed, and the description still names them briefly. Decision workflow, nesting, and the root-level edge case are all covered 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 coverage is 100%, so both parameters are already documented with descriptions that closely mirror the tool text. The description adds little beyond restating the parentFolderId workflow, so baseline 3 applies.

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 ('Create') and resource ('folder') with an explicit condition ('only when no existing folder fits') that distinguishes it from search and fetch_folder. An agent can immediately tell what this does and when it applies.

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: search with resultType folders first, fall back to fetch_folder and walk from root if needed, and reserve create for when no folder fits. Also gives the root-level exception for omitting parentFolderId. Covers when-to-use, alternatives, and exclusions.

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