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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description's real contribution is scoping the destruction — only the empty folder is removed, never its contents — but it says nothing about what happens on a non-empty folder (error? partial delete?) or about permission requirements, leaving a meaningful behavioral gap.

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?

Three short sentences, none wasted, with the action front-loaded before the precondition. Slightly clipped at the end, but every clause carries information.

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 mutating tool with no output schema, the description covers the essential facts: what it removes, the emptiness precondition, and what it will never remove. The main omission is failure behavior on a non-empty folder, which the agent would benefit from knowing.

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% with a single well-documented path parameter, so the baseline of 3 applies. The description adds no format, resolution, or path-rooting detail beyond what the schema's example already conveys.

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?

"Deletes a folder" is a specific verb plus resource, and "Files are never deleted by this tool" draws a clear line against the sibling delete_file. It stops short of explicitly naming the sibling it replaces or contrasting with rename_folder, so it is clear but not fully differentiated.

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 precondition is stated directly: the folder "must be empty: move or delete its files and subfolders first," which tells the agent when this tool will succeed and what workflow precedes it. It never names the specific sibling tools (move_file, delete_file) to use for that prep step, so the routing is implied rather than explicit.

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