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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the safety and retry profile is covered structurally. The description adds real behavioral context in the form of quota limits (5 per document, 10MB per file), but it does not say what happens when a limit is exceeded or how the attachment becomes available afterward.

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 purpose is front-loaded in one short sentence, which is good. However, the free-tier marker appears twice ('무료. [무료]'), an obvious duplication that wastes space and reads as an artifact rather than 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 4-required-parameter write tool with full schema coverage and annotations, the essential facts are present, but there is no output schema and the description does not indicate what is returned or how quota failures surface. An agent can call it, but cannot predict the result shape or error behavior.

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 coverage is 100%, and the schema already documents name-with-extension, base64 size, request_id deduplication semantics, and document_id. The description's 10MB note only restates the base64 schema constraint, so it adds no meaning beyond the structured fields.

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 a specific verb and resource ('내 문서에 파일을 추가합니다' = add a file to my document), which clearly separates it from sibling tools like document_attachment_list and document_attachment_remove. It lacks an explicit named alternative, but the action is unambiguous.

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?

It lists hard constraints (5 attachments per document, 10MB per file) but gives no guidance on when to use this versus alternatives such as document_download or the listing/removal siblings. There are no exclusions or prerequisite hints, so an agent must infer the usage context.

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