mf_list_billings

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

No annotations are provided, so the description carries full burden. It mentions filtering capabilities but doesn't disclose critical behavioral traits: whether this is a read-only operation, if it requires authentication, pagination behavior (implied by page/per_page parameters but not explained), rate limits, or what the return format looks like. For a list operation with 7 parameters, this leaves significant gaps.

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 extremely concise - just two short sentences in Japanese that state the core purpose and key filtering capabilities. Every word earns its place with zero redundancy or fluff. It's appropriately sized for a list operation.

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?

Given the tool's complexity (7 parameters, list operation) and lack of both annotations and output schema, the description is insufficient. It doesn't explain what the return value contains, how pagination works, authentication requirements, or error conditions. For a billing/list tool in what appears to be a financial system, more contextual information would be expected.

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 100%, so the schema already documents all 7 parameters thoroughly. The description adds minimal value beyond the schema by mentioning partner and period filtering (which corresponds to partner_id, from, and to parameters), but doesn't provide additional context about parameter interactions, default values, or usage examples.

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's purpose: '請求書一覧を取得します' (get a list of invoices). It specifies the resource (invoices) and the action (get/list), but doesn't explicitly differentiate it from sibling tools like mf_get_billing (which likely retrieves a single invoice) or mf_list_quotes (which lists quotes rather than 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 context by mentioning filtering capabilities ('取引先や期間で絞り込み可能です' - can filter by partner and period), which suggests when this tool might be preferred over unfiltered alternatives. However, it doesn't explicitly state when to use this tool versus siblings like mf_get_billing or mf_list_quotes, nor does it provide exclusion criteria or prerequisites.

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