create_folder

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

The description is transparent about return values, error cases, execution immediacy, audit logging, and reversibility. However, it contradicts the idempotentHint=true annotation by stating that a duplicate name yields an error object; an idempotent tool should return the same result on repeated identical calls. This is an annotation contradiction.

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, each carrying distinct information: purpose, return/error, execution/audit, and sibling distinction. No filler; front-loaded with the core action.

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 two-parameter tool with no output schema, the description covers return shape, error behavior, execution context, and the relevant sibling. The only notable gap is the idempotency inconsistency, which prevents a perfect score.

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 the schema already documents name and account_id. The description adds no parameter-specific meaning beyond the schema, 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'), resource ('mailbox folder'), and provider scope, and explicitly distinguishes from delete_folder. The purpose is immediately clear and not confusable with 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: executed immediately, no approval, harmless/reversible, and explicitly names delete_folder as the different approved tool for removal. It does not enumerate when to prefer list_folders, but the schema covers that, so this is a 4 rather than a 5.

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