Zaim API MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. '更新します' (updates) implies a mutation operation, but the description doesn't disclose any behavioral traits: no information about authentication requirements, rate limits, error conditions, whether the update is partial or complete, or what happens to unspecified fields. For a mutation tool with 11 parameters and no annotation coverage, this is a significant gap.

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, efficient Japanese sentence that directly states the tool's purpose: 'Zaimの既存の家計簿記録を更新します' (Updates Zaim's existing household account records). There's zero wasted verbiage or unnecessary elaboration. It's appropriately sized and front-loaded with the essential 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?

For a mutation tool with 11 parameters, no annotations, and no output schema, the description is incomplete. It doesn't explain what happens when the tool is invoked (response format, success indicators, error handling), doesn't mention authentication requirements despite sibling tools including auth-related tools, and provides no behavioral context. The description alone is insufficient for an agent to understand how to properly use this tool.

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 description coverage is 100%, with all 11 parameters having descriptions in Japanese. The tool description doesn't add any parameter-specific information beyond what's already in the schema. According to the scoring rules, when schema_description_coverage is high (>80%), the baseline is 3 even with no param info in the description, which applies here.

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 action ('更新します' - updates) and the resource ('Zaimの既存の家計簿記録' - Zaim's existing household account records). It distinguishes from sibling tools like zaim_create_income/payment/transfer by specifying it updates existing records rather than creating new ones. However, it doesn't explicitly mention what fields can be updated beyond the general concept.

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 no guidance on when to use this tool versus alternatives. There are sibling tools for creating records (zaim_create_income/payment/transfer) and deleting records (zaim_delete_money_record), but the description doesn't explain when updating is appropriate versus creating new or deleting existing records. No prerequisites or constraints are mentioned.

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