monthly_summary

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

No annotations are provided, so the description must fully disclose behavior. It states it aggregates and displays, which implies read-only, but it does not explicitly mention no side effects, data coverage, or any limitations. There is no contradiction, but the description adds minimal behavioral context beyond the obvious function.

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, front-loaded sentence that directly states the tool's purpose without extraneous details. It is appropriately concise for a simple tool.

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 tool is simple with two optional parameters and no output schema. The description covers the main purpose but does not explain the return format or any safety context that would normally be expected given the lack of annotations. However, for a low-complexity summary tool, it is reasonably adequate.

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 input schema covers both parameters (year and month) with descriptions and defaults, achieving 100% schema description coverage. The tool description adds no additional parameter semantics, so it does not exceed the baseline.

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 aggregates and displays a monthly income/expense summary by account category ('月次の収支サマリーを勘定科目別に集計して表示する'). This is a specific verb+resource scope and distinguishes it from sibling tools that list individual transactions or invoices.

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 implies usage for obtaining monthly summaries, but it does not explicitly state when to prefer this over list_deals, list_invoices, or pending_transactions. The context is clear but there are no explicit exclusions or alternative guidance.

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