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

Annotations already declare idempotentHint=true, and the description explains what that means concretely: it returns the existing folder if the name already exists. It adds uniqueness and case-insensitivity context beyond the annotation. It does not describe error handling or return format, but those are minor for a simple create/return tool.

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, zero waste. The first sentence front-loads the core purpose and idempotent behavior; the second gives usage guidance. No redundant phrasing.

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 single-parameter tool with comprehensive schema and annotations, the description covers purpose, behavior, and alternative routing. The absence of an output schema is acceptable for a create/return tool; the agent knows what to expect. Nothing critical 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 name parameter is fully documented. The description adds the semantic detail that names are unique per user and case-insensitive, which is not in the schema. This enriches the meaning of the parameter beyond the basic type and length constraints.

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 the exact action (create a folder by name) and the idempotent behavior (return existing one). It differentiates from document_create by explicitly saying to prefer its folder parameters when filing documents. It also clarifies uniqueness per user and case-insensitivity, making the purpose unambiguous.

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 explicitly names document_create as the alternative and states the condition for preferring it ('when the goal is to file a document'). This gives clear routing guidance. It also implies when to use this tool: when you want a folder by name, including reusing existing ones.

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