list_folders

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful scoping context (single account, dual IMAP/Gmail backends), but does not describe result shape, hierarchy, or whether labels and folders are returned differently.

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?

A single front-loaded sentence with no filler; the scope qualifier is stated immediately after the verb and resource.

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 one-parameter read-only listing tool with annotations covering safety and no output schema, the description is nearly sufficient. The remaining gap is what the listing returns (flat vs nested, label vs folder differences), which is minor but non-zero.

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?

There is a single parameter with 0% schema description coverage, so the schema does not document account_id at all. The description partially compensates by clarifying the account must be explicitly selected rather than inferred, but it adds no format, source, or lookup detail.

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 gives a specific verb (list) and resource (IMAP folders or Gmail labels) plus a clear scope (one explicitly selected account). It is distinguishable from siblings like list_accounts or search_messages, though it does not explicitly name or contrast with them.

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?

There is no explicit when-to-use or when-not-to-use guidance and no mention of alternatives. The phrase 'one explicitly selected account' hints that an account must already be chosen, but this is inferred rather than stated, and nothing routes the agent between this and list_accounts or search_messages.

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