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

The description goes well beyond the readOnlyHint/idempotentHint annotations by explaining that the balance is a snapshot tied to the last upstream sync, not a live read. It also discloses error/warning behavior for credit accounts, including specific error types and that failures surface as structured warnings rather than exceptions.

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 but well-organized: the main purpose and endpoint are front-loaded, followed by freshness caveats, sync guidance, and error behavior. A few details could be tightened, but every sentence contributes useful operational information.

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?

Since there is no output schema, the description partially compensates by mentioning relevant response fields (updateDateTime/updatedAt) and warning behavior. It does not fully describe the return payload structure, but for invoking the tool correctly the key behavior and error cases are covered.

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 reasonably by stating that account_ids is an array and adding the 1–50 size constraint that is absent from the schema. It could provide an example or clarify the meaning of each item further, but for a single parameter it is adequate.

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 uses a specific verb ('Returns') and resource ('latest available balance per account id'), names the REST endpoint, and clearly distinguishes its purpose from siblings like openfinance_list_transactions and openfinance_force_sync. An agent can tell exactly what this tool does.

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 provides concrete usage context: use this for the freshest balance the provider can serve, and if data seems stale or inconsistent with transactions, run openfinance_force_sync and re-read. It does not explicitly list 'when not to use' but it names the relevant alternative and the triggering conditions.

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