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

Beyond the annotations (destructiveHint=true, idempotentHint=true), the description discloses prerequisites, the exact monitoring window under three different plan situations, the 5-minute default check interval, and the idempotent behavior on already-active transfers. This is materially more than the structured fields provide.

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 core action is front-loaded and each sentence carries distinct information (prerequisites, duration rules, frequency, no-op case, return). The billing-period enumeration sentence is dense but earns its length given the branching conditions.

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?

With an output schema present, return details need not be restated, and the description still covers prerequisites, duration semantics, post-restore behavior, and the no-op case. Nothing an agent needs to decide whether and how to call it is missing.

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 100% schema description coverage, so the schema already carries the UETR meaning and format. The description adds no further parameter guidance, which is acceptable at this coverage level.

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 opening sentence gives a specific verb and resource ('Restore an archived transfer') plus the observable effect ('so its monitoring resumes'), which cleanly separates it from archive_transfer, delete_transfer, and recheck_transfer in the sibling list.

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 states the gating conditions (active subscription, a free active transfer place) and adds a useful no-op case: 'Restoring an active transfer changes nothing.' It also points to set_check_frequency as the way to alter cadence afterward. It stops short of naming archive_transfer as the inverse operation or saying what to do when no place is free.

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