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

It goes well beyond the readOnly/idempotent annotations by disclosing snapshot semantics, the upstream-sync anchor for updateDateTime/updatedAt, credit-account error/warning behavior, and upstream 5xx degradation. However, the final sentence about degradation is truncated, leaving one disclosed behavior incomplete.

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 front-loaded with the core purpose, and most sentences earn their place. However, it is dense and somewhat run-on, and the final sentence ends abruptly ('DEGRADES to the'), which hurts structural cleanliness.

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?

It covers freshness, error modes, warning rows, and the force-sync workflow, and there is no output schema to rely on. Yet it does not explicitly define the successful balance payload fields, and the truncated degradation sentence leaves a clear gap in coverage.

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?

The schema provides only a required string array `account_ids` with zero description coverage. The description adds the crucial constraint 'Pass account_ids as an array (1–50)', which gives the type, cardinality, and upper bound. It does not elaborate on the meaning of each ID, but the parameter name is self-explanatory.

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 specific action, resource, and endpoint: 'Returns the latest available balance per account id (GET /accounts/:id/balance)'. This clearly differentiates the tool from siblings like openfinance_list_transactions and openfinance_force_sync by anchoring it to a balance snapshot per account.

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 explicitly routes the agent: if a movement is not reflected or the balance disagrees with openfinance_list_transactions, it instructs to run openfinance_force_sync and then re-read. This gives a concrete when-to-use alternative, though it does not enumerate all cases where this tool should be avoided.

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