register_route_payid

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

With no annotations, the description carries the full behavioral burden. It usefully discloses idempotent-style behavior (re-calling returns the existing PayID) and the activation prerequisite, but omits permission/auth requirements, failure modes for inactive routes, and any rate or format details.

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?

Two sentences, no filler, with the core action and its benefit front-loaded and the idempotency caveat second. Every clause earns its place.

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 two-parameter mutation with no output schema, the description covers the action, the prerequisite state, and the repeat-call return behavior. It could say more about the resulting PayID's form or error conditions, but nothing essential to invoking 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?

Schema description coverage is 100% and both parameters already documented, so the baseline is 3. The description adds mild meaning by characterizing virtualAccountId as an activated AUD payment route, but does not clarify format or relationships beyond that.

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 specific verb (register), resource (PayID), and the exact target (an activated AUD payment route/virtual account), and explains the user-visible outcome (payers can send to an email-style alias instead of BSB/account). No sibling tool touches PayID, so there is no ambiguity to resolve.

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 a clear precondition — the route must already be activated — and clarifies the repeat-call case. It does not name alternative tools or state when not to use it, so it falls short of explicit when/when-not routing, but the context is unambiguous.

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