Sakila MCP Server

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. While '取得します' (get/retrieve) implies a read operation, there's no information about authentication requirements, rate limits, error conditions, response format, or whether this is a real-time query versus cached data. For a tool with no annotation coverage, this leaves significant behavioral gaps.

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 extremely concise - a single Japanese sentence that efficiently communicates the core functionality. It's front-loaded with the main purpose and includes the scope (address, rental statistics) without unnecessary elaboration. 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?

For a tool with no annotations, no output schema, and multiple sibling tools in the same domain, the description is insufficient. It doesn't explain what format the details come in, how comprehensive they are, whether this includes historical data, or how it differs from other customer tools. The agent would struggle to use this effectively without additional context.

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 description coverage is 100%, so the schema already documents both parameters (customer_id and email) with their descriptions. The tool description doesn't add any parameter-specific information beyond what's in the schema, nor does it explain the relationship between the two parameters or which takes precedence. Baseline 3 is appropriate when schema does the heavy lifting.

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 tool's purpose: '取得します' (get/retrieve) '顧客の詳細情報' (customer details) including '住所、レンタル統計含む' (address, rental statistics included). It specifies the resource (customer details) and scope (including address and rental statistics), but doesn't explicitly differentiate from sibling tools like get_customer_activity or get_customer_rentals.

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. With multiple customer-related tools available (get_customer_activity, get_customer_rentals, get_customer_segments, search_customers), there's no indication of when this detailed view is appropriate versus those other tools, nor any prerequisites or exclusions mentioned.

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