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

Annotations already declare destructiveHint=true and idempotentHint=false, but the description goes well beyond them: it discloses irreversibility, the copy-before-delete ordering, and the concrete partial-failure outcome ('a run that stops part-way leaves the folder split across both places'). That failure-mode detail is exactly the kind of behavioral context an agent cannot get from 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?

Four sentences, front-loaded with what happens and the irreversibility warning, then ordering semantics, then the prerequisite. No filler; the compound third sentence is dense but each clause carries distinct operational 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?

No output schema exists, yet the description covers prerequisites, failure modes, and formatting constraints, so an agent has enough to call it correctly. Gaps remain around when 'overwrite' is appropriate and when to prefer copy_prefix instead, which matter for a destructive bulk operation.

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%, so all six parameters are already documented in the schema. The description repeats the trailing-slash rule for both prefixes but adds nothing about the optional 'overwrite' parameter, so it does not exceed the baseline for a fully-covered schema.

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 concrete verb+resource ('Copies every object under a prefix to another prefix and then deletes each source'), which is precisely the copy-then-delete semantics that separates it from copy_prefix and delete_prefix. An agent can distinguish this from the single-object move_object and the non-destructive copy_prefix without opening any schema.

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?

Gives an explicit prerequisite workflow ('Call stat_prefix first and show the user what will move') and flags irreversibility, which implies caution. It never names copy_prefix or delete_prefix as alternatives, so the when-not-to-move choice is left to inference.

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