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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds domain semantics (tax exclusion and MAU-based banding) but does not disclose any additional behavioral traits such as authentication, rate limits, or response shape. No contradiction with annotations.

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 description is two short sentences with no filler. The core subject is front-loaded ('ステップ式の料金表 (税抜)'), and the second sentence adds necessary pricing context without redundancy.

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 zero-parameter, read-only list tool, the description and annotations cover safety and the essential pricing semantics. It is slightly incomplete in that it does not indicate what fields the returned pricing table contains, but the low complexity and clear subject make it adequate.

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?

The tool has zero parameters, so there is nothing for the description to document beyond what the schema already provides. A baseline of 4 is appropriate because no parameter ambiguity exists.

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 clearly identifies the resource as a step-based pricing table (tax-excluded) and distinguishes it from sibling tools like list_users or list_credentials by its subject matter. It lacks an explicit verb such as '取得する' or '一覧表示する', so it is clear but not a fully specified action statement.

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?

No explicit guidance is given about when to call this tool versus alternatives, and no when-not-to-use conditions are provided. The description explains how pricing works (MAU bands determine the monthly fee), which is useful context, but it never states the intended invocation scenario.

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