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

Beyond the annotations (idempotent, non-destructive, open-world), the description discloses that plan tier governs monitoring, that a duplicate UETR returns the existing transfer and consumes no additional plan quota, and that archived transfers come back archived. It omits failure behavior such as plan limits being exceeded or invalid UETR handling.

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 tight sentences, front-loaded with what the tool does and immediately followed by the plan/duplicate consequences. The phrase 'as for an add on the website' is a slightly ambiguous appeal to outside behavior.

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 a rich schema, an output schema, and annotations present, the description supplies the non-obvious parts: plan-driven monitoring and idempotent/archived behavior. Only error and quota-exhaustion paths are left unexplained.

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% and already documents every parameter including currency list and date bounds. The description restates the same three inputs without adding format or constraint detail, so baseline 3 applies.

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 and resource: 'Add a transfer to the account by its UETR', with the identifying inputs named. It is distinguishable from get_transfer/update_transfer by the word 'add', though the description never explicitly contrasts with those siblings.

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?

Usage is only implied — the reader infers this is the enrollment/creation path because it adds to 'the account's plan'. There is no explicit when-to-use or when-not guidance relative to get_transfer, recheck_transfer, restore_transfer or update_transfer.

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