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

Annotations declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false; the description does not contradict these and adds genuinely useful behavior: currency is hard-locked to USD and other values are rejected, bare domains in institution_login_url are normalized to https, Plaid-linked accounts get a login URL automatically, and include_in_debt_paydown explicitly does NOT affect net worth, total debt, or the balance sheet. It stops short of explaining duplicate-account behavior or what happens on partial failure, which would be relevant given idempotentHint=false.

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?

Long, but each parameter entry earns its place given 23 undocumented-in-schema fields, and the one-line purpose statement is front-loaded. The trailing 'Returns: Created account details' is near-vacuous but minor. Some entries (currency's docs-file reference) are slightly noisy but still informative.

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 23-parameter creation tool with no output schema and only hint-level annotations, this is close to complete: it covers defaults, valid ranges, enum values, and cross-parameter applicability rules. Remaining gaps are return-shape detail (addressed minimally), duplicate/idempotency behavior, and error conditions like invalid account_type values, which matter given idempotentHint=false.

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 0% and there are 23 parameters, so the description carries the full burden — and it largely does. It enumerates all 11 valid account_type values (the schema has no enum), gives examples and units for name, balance, interest_rate (0-100 annual %), term_months (360 = 30-year mortgage), dates in YYYY-MM-DD, and scopes conditional parameters (escrow fields = mortgage only, draw fields = HELOC only, low-balance fields = checking/savings/cash only). This is meaning far beyond what the bare typed schema provides.

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 a new financial account'), which distinguishes it from sibling creators like create_transaction, create_goal, or create_hard_asset by resource type. It does not explicitly name those alternatives, but the resource noun plus the account_type enumeration makes the scope unambiguous.

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?

No guidance on when to use this versus import_accounts, create_hard_asset, or list_accounts-then-act workflows. There is also no mention of prerequisites (e.g. whether the account must be linked to a Plaid item afterward). The description moves straight into parameter documentation with no usage context at all.

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