Retrieve a dynamic virtual account by your reference

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world behavior, so the safety profile is covered. The description still adds real value by disclosing the failure mode: an unknown reference yields 404 resource_missing. It stops short of describing the returned object's shape, but the error contract is the main behavioral gap an agent needs.

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 content is front-loaded and tightly written: identity of the tool, its precondition, its exclusion, and its error case in two short sentences. The opening line largely restates the title, which is the only wasted wording.

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 lookup with full annotation coverage, the description supplies everything needed to choose and call it, including the 404 case. The only minor omission is that no output schema exists and the description says nothing about what the returned account object contains.

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 single parameter is already documented. The description reinforces that the reference is the one given at creation and is the same as the associated payment's reference, which clarifies provenance but adds little beyond the schema text.

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 names a specific verb and resource ("Retrieve a dynamic virtual account"), and crucially scopes it to dynamic accounts retrieved by reference. It explicitly contrasts this with dedicated accounts, which have no reference, and points to the id/list alternatives, so an agent can distinguish it from get_virtual_account without opening either 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?

It states the exact precondition (a reference you supplied at creation time) and an explicit exclusion: dedicated accounts have no reference and must be fetched by id or listed by customer. That is a genuine when-to-use / when-not-to-use rule plus the fallback path.

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