Rebillia 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. It states this is a read operation ('View') and mentions the return data (scheduled charges with amounts and dates), but lacks details on permissions, rate limits, error handling, or pagination. For a tool with no annotations, 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 front-loaded with the core purpose, followed by API endpoint and return details. It's efficient with three sentences, though 'Optional: include' is somewhat vague and could be integrated more smoothly. Overall, it avoids unnecessary verbosity.

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 basic purpose and return info but lacks details on behavioral traits (e.g., auth needs, error cases) and doesn't fully explain the 'include' parameter. It's adequate for a simple read tool but has clear gaps in context for an AI agent.

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 ('subscriptionId' as required, 'include' as optional). The description adds minimal value by mentioning 'Optional: include' but doesn't explain what 'include' does or provide examples. Baseline 3 is appropriate when the 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 with a specific verb ('View') and resource ('upcoming charges for a subscription'), and mentions the types of charges returned (recurring, one-time, usage). However, it doesn't explicitly differentiate this tool from sibling tools like 'get_subscription' or 'get_subscription_invoices', which might also provide subscription-related information.

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 prerequisites, such as needing an existing subscription, or compare it to other subscription-related tools in the sibling list (e.g., 'get_subscription' for general info or 'get_subscription_invoices' for past charges).

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