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

With no annotations, the description carries the full behavioral disclosure burden. It reveals that the tool moves messages and then deletes the emptied folders, making the destructive nature reasonably clear. It could go further by explicitly stating that the deletion is irreversible or describing subfolder behavior, but the core behavior is disclosed.

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 two sentences with no filler. The first sentence front-loads the main behavior, and the second adds a critical safety instruction. Every sentence earns its place.

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 destructive merge operation with no annotations and no output schema, the description covers the main purpose, the actions performed, and the confirmation requirement. Minor gaps remain—such as irreversibility and behavior with subfolders—but the essential guidance is present.

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 parameters are already well documented. The tool description reinforces the relationship between folderIds and keepFolderId but does not add meaningful details beyond what the schema already explains.

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 clearly states a specific action sequence: move every message from a set of duplicate folders into one folder, then delete the emptied folders. This distinguishes it from sibling tools like delete_mail_folder or move_messages by describing the combined merge-and-delete behavior.

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 clearly identifies the tool's context—duplicate mail folders—and includes an explicit instruction to ask the user for confirmation before calling. It does not explicitly name alternatives or state when not to use it, so it stops short of a perfect usage-guideline score.

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