units.data_size_convert

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

Annotations already declare readOnlyHint and idempotentHint, so the description focuses on domain behavior and adds genuinely useful facts: strict case sensitivity with 'KB' being an error, which unit tables each mode accepts, and that magnitude must be a non-negative Decimal string. It does not describe output shape, but an output schema exists so that burden is covered.

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?

Three dense sentences with no filler, front-loaded on the core action before drilling into mode and validation rules. The unit lists are long but each item earns its place because the schema offers no enums.

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 four parameters with zero schema documentation, a read-only/idempotent annotation profile, and an existing output schema, the description covers everything needed to call it correctly. A brief note on what the returned value looks like or how invalid from_unit/to_unit combinations are reported would make it complete.

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 0%, so the description must carry all four parameters, and it does: 'mode' is enumerated with its default and per-mode unit tables, 'from_unit'/'to_unit' are constrained by case sensitivity and table membership, and 'magnitude' is constrained to a non-negative Decimal string. This adds far more meaning than the bare string-typed schema 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?

States a specific verb and resource ('데이터 크기 단위를 바이트 기준으로 변환한다') that clearly identifies a data-size unit conversion. It is distinguishable from generic siblings like units.convert or engineering.si_prefix_convert in practice, but never names or contrasts them, leaving the agent to infer the boundary.

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?

Usage is implied by the unit tables and default mode, and the description explains how to pick between 'si'/'iec'/'mixed', which is real routing guidance. However, there is no statement of when this tool should be chosen over units.convert or si_prefix_convert, and no exclusions or prerequisites.

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