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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns counts broken down by current status, which is a behavioral detail beyond the schema. However, it doesn't mention whether the listing is paginated, ordered, or requires any authentication/scoping, so it only partially covers behavioral expectations.

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 sentences, no waste, with the key behavioral note (why current counts are split) front-loaded after the main purpose. The description earns every word and is easy to scan.

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 simple list tool with two optional parameters and no output schema, the description covers the purpose and the rationale for the count breakdown. However, it omits any mention of the return format or whether the listing is sorted/filtered beyond the parameters; not critical for a list tool, but slightly incomplete given no annotations or output schema.

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% (both parameters have descriptions in the schema), so the description adds little beyond what the schema already provides. The description's mention of '素性ごと、現行かどうかごとに数えたもの' implies the 'only_current' parameter's relevance, but it doesn't add syntax or format details; baseline 3 is appropriate.

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 the tool lists sources ('出典の一覧') and mentions it returns counts by feature and currency, which distinguishes it from generic sibling tools like jhnrd_get_source. However, it doesn't explicitly name the operation 'list' as a verb or contrast it with a sibling; the resource is clear but the differentiation is implicit.

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?

The description explains why the counts are split between current and total ('statute が何件あるかだけを言うと実態より良く見えるので、現行版の数を分けて出す'), giving context for how the output should be interpreted. It doesn't explicitly say when to use this tool versus alternatives like jhnrd_search or jhnrd_list_items, but the context is clear enough for a simple list operation.

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