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

The annotations declare read-only/idempotent behavior, but the description adds substantial non-obvious behavioral context: `balance` semantics vary by connector, `balance_notice` means a zero value may be misleading, `bankData` fields can lag after connection creation, and `provider_incident`/`identity_notice` warn about unreliable or misattributed data. This far exceeds what the annotations convey.

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?

Although long, the description is front-loaded with a clear summary and then organized into distinct, high-value caveat blocks. Every paragraph addresses a real decision an agent would otherwise get wrong, such as treating credit balance as the current bill or presenting incident-affected values as real.

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?

There is no output schema, so the description carries the full burden of explaining return semantics. It covers the main fields, connector-specific caveats, notice blocks, and bulk execution, making it sufficiently complete for a tool of this complexity.

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?

With 0% schema description coverage, the description compensates well for `item`, `item_ids`, and `type`, explaining their meaning and consequences. However, it never explicitly explains the singular `item_id` input parameter, and the relationship between `item` and `item_id` is left implicit, creating a small but real gap.

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 opens with a precise verb and resource: 'Returns accounts for a bank connection' and enumerates the account types and returned data. It also clearly distinguishes itself from the sibling openfinance_list_credit_card_bills, so an agent can tell them apart without opening schemas.

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 explicitly says when to omit `item` to list all connected banks, when to pass `item` for a single bank, and when to use openfinance_list_credit_card_bills instead for standardized bill amounts. This gives an agent a clear decision procedure rather than leaving usage to inference.

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