run_rakuten_categories

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

With no annotations, the description carries the full burden. It usefully discloses output content (breadcrumb path, child genres with item counts) and the cost model ('Flat 5 points per successful run'), which is genuinely beyond structured fields. It says nothing about pagination, rate limits, or error behavior, so the disclosure remains partial.

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?

Two compact sentences, front-loaded with the resource and modes before the cost note. No filler, no repetition of the tool name or title.

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 one-optional-param lookup with no annotations and no output schema, the description covers both invocation modes, the returned structure, and the cost. Error and limit behavior are unaddressed, which is a minor gap given the tool's simplicity.

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 labels genre_id as 'Genre ID (optional)', but the description adds real meaning by stating what omitting vs. supplying it returns. That behavioral mapping of the parameter exceeds the baseline for a schema-covered single param.

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 names a specific verb and resource ('Rakuten Ichiba genre tree') and spells out both operating modes: top-level genres, or a single genre by id with breadcrumb path and child genres. An agent can distinguish this from sibling category tools like run_olx_categories or run_ebay_category without opening any schema.

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 clearly communicates the selection condition — omit genre_id to browse the tree, supply it to get one genre with breadcrumb and children. However, it names no alternatives or exclusions (e.g., when to reach for run_rakuten_items_search instead), so it stops short of full when/when-not guidance.

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