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

No annotations exist, so the description carries the full burden and it discloses almost nothing: not that OTP from the authenticator app is required and will be consumed, not that this is an irreversible mutation, not whether external payees need validation. Only the split between NorthPark and external payees hints at differing behavior.

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?

A single front-loaded sentence with zero filler. It is efficient, though the brevity borders on under-specification for a 5-parameter mutation tool.

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 5 parameters (4 required), no annotations, no output schema, and 40% schema coverage, the definition leaves major gaps: authentication flow, external-vs-bank conditional fields, and failure modes are all unaddressed.

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 only 40% – bank, name, and account_id have no descriptions at all. The phrase 'external US payee' weakly implies the bank enum's 'external' value and that routing_number applies only there, but the description never explains the required OTP, the account_id format, or the conditional routing number.

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 gives a specific verb (Add) and resource (payee) and distinguishes the two payee categories, NorthPark (in-network) vs external US. An agent knows what entity gets created, though it doesn't explicitly contrast with siblings like list_payees or make_payment.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites (an OTP is required, routing number conditional on external), and no note about what happens if the payee already exists. The agent must infer everything from the schema.

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