Rebillia 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. It discloses that the tool is a GET operation (implying read-only), returns paginated results, and includes filtering behavior (case-insensitive status/type filters). However, it does not mention authentication needs, rate limits, error conditions, or response format details beyond a brief attribute list.

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 front-loaded with the core purpose and HTTP method, followed by return details and optional parameters. It is relatively concise but includes some redundancy (e.g., repeating 'case-insensitive' for both status and type). Every sentence adds value, though it could be slightly tighter.

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 no annotations and no output schema, the description provides adequate context for a read operation with filtering and pagination. It covers the main purpose, key parameters, and return attributes, but lacks details on authentication, error handling, or full response structure. For a tool with 8 parameters and no structured output documentation, it is minimally complete but has 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?

Schema description coverage is 100%, so the schema already documents all 8 parameters thoroughly. The description adds minimal value by mentioning that status/type filters are case-insensitive and listing some return attributes, but does not provide significant additional semantics beyond what the schema specifies. Baseline 3 is appropriate given high schema coverage.

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 ('List') and resource ('rate plans on a subscription'), specifying it returns paginated rate plans with key attributes. It distinguishes from siblings like 'get_subscription_rate_plan' (singular) by emphasizing listing multiple items with filtering options.

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 for retrieving rate plans with optional filtering, but does not explicitly state when to use this tool versus alternatives like 'get_subscription_rate_plan' (for a single rate plan) or 'list_subscriptions' (for subscriptions themselves). It provides context on filtering capabilities but lacks explicit comparison.

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