list_folders

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

Goes well beyond the readOnly/non-idempotent annotations by disclosing pagination mechanics, cursor single-use, and a 10-minute cursor expiry. These are non-obvious operational traits an agent must know to avoid replaying a stale cursor, and they cannot be inferred from the schema or annotations.

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?

Five short sentences, front-loaded with the core operation then scoping, defaults, and pagination in descending order of importance. No filler and nothing redundant with the schema.

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?

Output schema exists so return shape need not be described; the description instead covers the reusable concerns an agent needs—traversal depth, starting point, paging protocol, and cursor lifetime. Complete for a list tool of this complexity.

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 0%, so the description must carry parameter meaning, and it largely does: limit default 20 / max 100, parent_folder_id's effect on traversal start, and cursor reuse semantics. store_id's role is left implicit, which keeps it from a 5, but the compensation for the coverage gap is substantial.

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 and resource ('List immediate child folders') and constrains scope explicitly ('Does not recurse'), so the agent knows exactly what set is returned. The sibling tools are email-related, and this description leaves no ambiguity about which tool this is.

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?

Explains the default starting point ('store root unless parent_folder_id is given') and gives concrete pagination procedure ('Follow next_cursor with the same arguments; limit may change'). It does not name an alternative tool or a when-not-to-use condition, but no sibling competes for this task, so the guidance is sufficient in context.

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