CreateAccount

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

Annotations already declare this is a non-read-only, non-idempotent, non-destructive, open-world write. The description adds genuinely useful behavioral context beyond that: the account is created *unlinked* (no bank connection), and the account_type choice determines whether the account counts toward the budget. It does not mention permission requirements or duplicate-name behavior, so not a 5.

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, zero filler, and the core action is front-loaded before the account-type consequence. 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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. The description covers the mutation's scope and the account-type semantics; only minor gaps remain (permissions, duplicate handling) for a 4-param creation tool.

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 the baseline is 3; however the description adds semantic meaning the enum alone cannot convey — which account types are on-budget (checking, savings, cash, creditCard) versus tracking (otherAsset, otherLiability). That is real added value over the 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 specific verb and resource ('Create an unlinked account') plus the required starting balance, and clarifies the on-budget vs tracking distinction. It does not explicitly differentiate itself from any sibling (e.g., Ynab_ImportTransactions, which can also materialize accounts), so it stops short of a 5.

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?

The description implies the use case (opening a new manual/unlinked account) and explains which account_type values map to on-budget vs tracking accounts, but it never states when to use this versus alternatives or any prerequisite/ordering constraints. Implied usage only.

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