ecount_save_invoice

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

With no annotations, the description carries full responsibility for behavioral disclosure. It reveals the most critical trait: this tool does NOT issue electronic tax invoices, only prepares the journal entry. This is valuable context. However, it does not mention side effects, idempotency, validation behavior, permissions, or error handling, leaving gaps in transparency beyond the single boundary condition.

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 exceptionally concise: two sentences that immediately state the action, scope, and critical limitation. It is front-loaded with the primary purpose, includes a useful manual reference, and contains no redundant or filler content.

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 moderate complexity (one nested array parameter) and the presence of an output schema, the description adequately covers the most crucial contextual boundary: the distinction between journal entry preparation and actual tax invoice issuance. It also points to the manual for full parameter details. However, it omits operational prerequisites or failure behavior, which would push it to a 5.

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 already provides 100% coverage with detailed descriptions of the 'invoices' array items, including required keys like TAX_GUBUN, CR_CODE/DR_CODE, and optional fields like TRX_DATE and REMARKS. The tool description adds only a manual reference ($9) and does not supplement parameter meaning beyond the schema. Hence, baseline 3 applies.

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 function: 'Enters sales/purchase slip II automatic journal entries' (매출·매입전표 II 자동분개를 입력한다). It also distinguishes itself from siblings by clarifying that actual e-tax invoice issuance is outside OAPI scope, implying ecount_web_export_tax_invoices or human action covers that, while ecount_save_customer is for customers. This is a specific verb+resource with clear differentiation.

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 clear context on when to use: for automating accounting journal entries up to but not including the actual tax invoice issuance. It explicitly states the tool's limitation ('actual e-tax invoice issuance is handled by a person after review in ecount ERP (outside OAPI scope)'), which helps avoid misuse. However, it does not explicitly name alternative sibling tools or provide step-by-step usage conditions, so it falls slightly short of a 5.

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