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

Adds substantial behavioral context beyond the readOnly/idempotent annotations: the result is a snapshot tied to the last upstream sync, not a live read; credit accounts may return structured warnings instead of throwing; and upstream 5xx or non-Open Finance connectors also degrade to warnings. This meaningfully changes how an agent should interpret and react to results.

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 dense and front-loaded with purpose, then walks through the most important caveats: snapshot freshness, remediation via force_sync, array size, and error degradation. Every sentence contributes a distinct operational point and there is no filler.

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?

The description covers the key operational semantics: freshness, remediation, parameter limits, and warning behavior. Since there is no output schema, it could have explicitly described the success payload fields such as balance amount and currency, but the endpoint path plus 'balance per account id' gives enough context for correct invocation and interpretation.

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 by directly instructing the agent to pass account_ids as an array of 1–50 elements. It does not elaborate on the exact string format of each id, but the parameter name plus 'per account id' makes that inferable.

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?

Opens with a specific verb and resource: 'Returns the latest available balance per account id' and names the exact endpoint (GET /accounts/:id/balance). It also differentiates itself from sibling tools by emphasizing it is a snapshot and directing the agent to openfinance_force_sync when freshness matters.

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?

Explicitly states when to use force_sync and re-read: if a recent movement is missing or the balance disagrees with openfinance_list_transactions. It also gives concrete handling guidance for credit-account errors (reconnect the bank) and upstream failures, which helps the agent choose not to treat all errors identically.

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