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 the tool 'analyzes' category performance, but doesn't describe what the analysis includes (e.g., metrics like sales, rentals, or trends), whether it's a read-only operation, any rate limits, or what the output format looks like. For a tool with no annotations, 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, efficient sentence in Japanese (カテゴリ別パフォーマンス分析を行います), which translates to 'Performs category performance analysis.' It is front-loaded with the core purpose and has zero wasted words, making it highly concise and well-structured for its minimal content.

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 of a performance analysis tool with no annotations and no output schema, the description is incomplete. It doesn't explain what 'performance' means, what metrics are returned, or how the analysis is structured. Without this context, users lack essential information to understand the tool's behavior and outputs, making it inadequate for effective use.

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 input schema has 100% description coverage, with clear documentation for both parameters ('period' and 'store_id'), including enums and defaults. The description adds no additional meaning beyond what the schema provides, such as explaining how these parameters affect the analysis. However, since schema coverage is high (>80%), the baseline score of 3 is appropriate, as the schema adequately handles parameter semantics.

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 states the tool performs 'category performance analysis' (カテゴリ別パフォーマンス分析を行います), which is a clear purpose. However, it lacks specificity about what 'performance' entails (e.g., sales, rentals, revenue) and doesn't distinguish it from sibling tools like 'list_categories' or 'get_revenue_summary', making it somewhat vague. The verb 'analyzes' is appropriate but could be more precise.

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 any context, prerequisites, or exclusions, such as how it differs from 'list_categories' (which might list categories without performance data) or 'get_revenue_summary' (which might provide overall revenue without category breakdown). Without such information, users must infer usage from the tool name alone.

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