mfc_ca_postJournals

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

Annotations are absent, so the description carries the full burden. It does disclose that this writes to books and requires user approval, covering the mutation and authorization aspects. However, it does not mention potential side effects, validation behavior, or the experimental invoice_kind handling beyond the schema note. Adequate but minimal.

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?

A single sentence that is front-loaded with the action and the approval constraint, with zero filler. It is appropriately sized for a simple create tool and efficient, though it could afford a bit more context without hurting clarity.

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 mutating tool with a complex nested parameter and no output schema, the description is sparse. It lacks examples, required-field emphasis, error behavior, or relation to the other journal endpoints (get, put, delete). The schema provides structure but not usage context, leaving an agent under-informed for correct invocation.

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%, with the journal object's structure and the invoice_kind note fully described in the schema. The description adds no parameter-specific guidance. Baseline 3 applies since the schema already carries the semantic load.

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 states 'Create journal entries (book write-in. Requires user approval)' – a clear verb and resource. The 'post' prefix and '作成' (create) make the action unambiguous relative to sibling update/delete tools. However, it does not explicitly name those alternatives, so differentiation is implied rather than stated.

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 explicit when-to-use guidance or alternative tools are mentioned. The approval note ('要ユーザー承認') hints at an operational constraint but does not help an agent choose between this and putJournals or deleteJournals. It relies on naming conventions for selection.

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