Retrieve the real-time balance of a specific bank account using its account ID, subject to institution support and limits.
Saldo em tempo real, sujeito ao suporte e limites da instituição.
| Name | Required | Description | Default |
|---|---|---|---|
| account_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| ok | Yes | ||
| data | No | ||
| meta | Yes | ||
| tool | Yes | ||
| error | No | ||
| warnings | Yes | ||
| pagination | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds the useful caveat that the real-time balance depends on institution support and limits, and that the value may vary in freshness. However, it does not disclose error behavior, fallback behavior, or what happens when the institution does not support real-time balance.
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 a single short sentence and the core value ('real-time balance') is front-loaded. It is concise, though the institutional-support caveat is a bit vague and could have been expressed more directly.
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?
This is a simple one-parameter read-only tool, and the output schema exists, so the description does not need to explain return values. Still, the description provides no usage guidance and leaves ambiguity about how this differs from get_total_balance, making it minimally viable but not complete.
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 should compensate. It does not explain account_id, its ownership, or any constraints beyond the schema's uuid format. The parameter name is self-explanatory, but no additional meaning or usage context is provided.
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 names the resource ('Saldo em tempo real' – real-time balance) and the operation is clearly implied by the tool name get_account_balance. It is distinguishable from sibling tools like get_total_balance, but it lacks an explicit verb and does not state the scope precisely.
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?
No guidance is given about when to use this tool versus alternatives such as get_total_balance or get_account. The caveat 'sujeito ao suporte e limites da instituição' hints at limitations but does not provide conditions, exclusions, or alternative tool references.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.