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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description still adds genuinely non-obvious domain behavior: 9-digit codes use different schemes for exports vs imports and each result's flow field must be checked. It does not describe result shape or paging, but the code-collision warning is the useful part.

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?

Front-loaded with the one-line purpose, then the usage rule, then the code caveat. The bilingual duplication doubles the length, but for a Japanese-first tool that is justified rather than waste.

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?

With no output schema, an agent still gets the crucial interpretation note that results must be disambiguated by flow, which is the main thing that could go wrong here. Minor gap: it does not say results are a list of name/code/flow entries, so the return shape is only implied.

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% and all five params carry their own descriptions, including the enum meanings, so the baseline is 3. The description only reinforces the flow parameter's significance and says nothing extra about q matching rules beyond what the schema already states.

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 ("Find items by name or code") and adds an implicit split from the lookup siblings via "Use this first when you do not know the code." It never names get_item explicitly, so the differentiation with the by-code lookup tools is inferable 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?

"Use this first when you do not know the code" gives a clear selection rule against the get_item/get_item_summary family. No explicit exclusion (e.g. when to skip straight to get_item) is spelled out, but the ordering guidance is actionable.

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