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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description discloses important behavioral nuances: `balance` semantics for CREDIT are connector-dependent, `balance_notice` means the balance was reported as zero despite an outstanding amount, `bankData` fields can lag after connection creation, and `provider_incident`/`identity_notice` can make values unreliable or require deduplication. This is far beyond what the annotations alone 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?

The description is long but carefully organized: purpose first, then usage modes, then important behavior caveats, then bulk support. Every section addresses a behavior or decision the agent needs, and the most critical scoping guidance ('OMIT item...', 'Pass item...') is front-loaded rather than buried at the end.

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 no output schema, the description must compensate by explaining the shape and meaning of the response. It does so thoroughly, covering aggregated results, per-row tagging, credit-card balance issues, provider incidents, identity notices, and stale bankData. For a tool with this many edge cases, the description is complete enough for an agent to call it correctly and interpret results safely.

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%, so the description carries the full burden. It explains `item` (omit for all banks, pass to target a single bank), implies `type` semantics by describing BANK and CREDIT, and explains `item_ids` bulk support. However, the `item_id` parameter is not explicitly described as an input, even though it appears in the schema, so the coverage is not fully complete.

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 clearly states the tool returns accounts for a bank connection, specifying BANK and CREDIT account types and the fields returned (balance, number, type, subtype, bankData, creditData). It also distinguishes itself from related tools by directing users to openfinance_list_credit_card_bills for standardized bill amounts, and the resource being acted on is explicit and specific.

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 gives explicit usage guidance: omit `item` to list accounts across all linked banks when the user says 'my accounts/cards' without naming a bank, and pass `item` to target a single bank. It also recommends openfinance_list_credit_card_bills for standardized open-bill amounts and when `balance_notice` is present, which clearly routes the agent to the correct alternative.

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