rails_lens_list_models

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

Annotations already declare the tool is read-only, idempotent, and not destructive. The description adds no additional behavioral context, such as whether models are fetched live or cached, if the list includes all models (e.g., system vs. application models), or performance implications. Given the annotations, a higher score would require extra value beyond them.

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 a single concise sentence in Japanese that directly states the purpose. It is front-loaded and contains no extraneous information. Every word earns its place.

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?

The description is sufficient for a simple list tool with no parameters and an output schema present. It clearly states what the tool retrieves. However, it could be more complete by clarifying whether the list includes all models or only those in certain namespaces, but the presence of an output schema mitigates this gap.

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 no parameters (schema coverage 100%). The description correctly mentions no parameters, so it doesn't need to add meaning beyond the schema. Baseline score of 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 name 'list_models' and description 'Railsアプリのモデル一覧を取得' clearly state the tool's purpose: retrieving a list of models in a Rails application. It uses a specific verb (list) and resource (models), and distinguishes from siblings like 'introspect_model' (single model) and 'get_schema' (database 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?

The description implies usage when a list of all models is needed. While no explicit guidance on when not to use is given, the context of sibling tools (e.g., 'introspect_model' for details) makes the use case clear. No alternatives or exclusions are stated, but the tool's simplicity and uniqueness make this acceptable.

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