rakuten-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure but only states the basic action without details on permissions, rate limits, error handling, or response format. It doesn't mention whether this is a read-only operation, if it requires authentication, or what the output looks like, leaving significant gaps for an agent to understand its behavior.

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, efficient sentence that directly states the tool's purpose without unnecessary words. It's front-loaded and appropriately sized for the complexity of the tool, making it easy to parse quickly.

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?

Given the tool's moderate complexity (3 parameters, no annotations, no output schema), the description is incomplete. It lacks information on behavioral traits, output format, and usage guidelines, which are crucial for an agent to invoke the tool correctly without structured data to fill these gaps.

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 description doesn't add any parameter semantics beyond what the input schema provides, which has 100% coverage with detailed descriptions for all parameters. Since the schema fully documents the parameters, the baseline score is 3, as the description doesn't compensate or add extra context about the parameters' usage or meaning.

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 states the verb 'Get' and resource 'reviews for a specific Rakuten product', making the purpose understandable. However, it doesn't explicitly differentiate from sibling tools like 'search_products', which might also return reviews or product information, leaving some ambiguity about when to use this specific tool versus alternatives.

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 provides no guidance on when to use this tool versus alternatives like 'search_products' or other siblings. It lacks context about prerequisites, such as needing a specific item code format, and doesn't mention any exclusions or scenarios where other tools might be more appropriate.

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