Sakila MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states what the tool does ('get popular film rankings') without detailing aspects like authentication requirements, rate limits, error handling, or the format of returned data. For a tool with no annotations and no output schema, this is a significant gap in transparency.

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, clear sentence in Japanese that directly states the tool's purpose without unnecessary words. It's front-loaded with the core action and resource, making it efficient and easy to parse. There's no wasted verbiage, earning a top score for conciseness.

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 complexity (4 parameters, no annotations, no output schema), the description is incomplete. It lacks details on behavioral traits, output format, and usage context. While the schema covers parameters well, the overall tool understanding is insufficient for an agent to invoke it confidently without additional context or assumptions.

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 adds no parameter-specific information beyond what's in the input schema, which has 100% coverage with descriptions for all parameters (e.g., 'period' with enum values, 'category' for filtering). Since schema description coverage is high, the baseline score is 3, as the schema adequately documents parameters without needing extra details in the description.

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: '人気映画ランキングを取得します' translates to 'Get popular film rankings.' This specifies the verb ('get') and resource ('popular film rankings'), making the purpose unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'get_top_customers' or 'get_category_performance,' which also retrieve rankings but for different entities.

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. It doesn't mention sibling tools like 'search_films' or 'get_film_details' that might serve related purposes, nor does it specify prerequisites or contexts where this tool is preferred. The lack of usage guidelines leaves the agent to infer based on tool names alone.

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