yahoo_list_folders

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

With no annotations, the description carries the full burden of behavioral disclosure. It adds useful context by stating that it returns folder names and explains the account default behavior, but it omits any authentication requirements, rate limits, or error behavior. A read-only listing is low-risk, but the absence of annotations leaves gaps.

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?

The description is front-loaded with the purpose, but the second sentence ('Returns folder names available in the Yahoo mailbox') largely repeats the first sentence. Since an output schema exists, this return-value sentence may not earn its place, creating redundancy.

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 simple list tool with one optional parameter and an output schema, the description covers purpose and parameter behavior adequately. It does not address authentication, but the low complexity and presence of an output schema make the definition largely complete.

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% for the single optional account parameter, so the description must compensate. It does so effectively by explaining that account="<key>" refers to another account in accounts.json, and that omitting it uses the default account marked in that file. This fully clarifies the parameter's semantics beyond what the schema provides.

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 a specific verb and resource: 'List all mailbox folders.' This clearly distinguishes the tool from mail-related siblings like yahoo_list_mail and yahoo_get_mail. However, it does not explicitly differentiate itself from other folder-related siblings such as yahoo_create_folder or yahoo_empty_folder.

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?

The description provides no guidance on when to use this tool versus alternatives. The only usage instruction concerns the account parameter, not tool selection. There is no mention of prerequisites or conditions under which folder listing is appropriate.

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