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 of behavioral disclosure. It adds context by explaining the meanings of status values (e.g., 'archived – subscription is ended/archived (use instead of delete when ending)'), which clarifies behavioral outcomes. However, it doesn't cover other traits like permissions needed, rate limits, or response format, leaving gaps for a mutation tool.

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 appropriately sized and front-loaded, starting with the core purpose. It efficiently lists status meanings in a clear, bullet-like format without unnecessary details. However, including the HTTP method ('PUT /subscriptions/{subscriptionId}/status') is slightly redundant since it's implied by the tool name, but it doesn't significantly detract from 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 tool's complexity (a mutation with 2 parameters), no annotations, and no output schema, the description is moderately complete. It explains the action and status semantics but lacks details on permissions, error handling, or return values. For a tool that updates subscription states, this leaves some contextual gaps, making it adequate but not fully comprehensive.

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' and 'status') with descriptions. The description adds value by elaborating on 'status' meanings (e.g., 'active – subscription is active and billing'), providing semantic context beyond the schema. This justifies a baseline score of 3, as the schema does heavy lifting but the description enhances understanding.

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: 'Update a subscription status.' It specifies the verb ('Update') and resource ('subscription status'), making the action explicit. However, it doesn't differentiate from sibling tools like 'update_subscription' or 'update_subscription_rate_plan', which handle other aspects of subscriptions, so it misses full sibling distinction.

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 by listing status meanings (e.g., 'active – subscription is active and billing'), which suggests when to use specific statuses. However, it doesn't explicitly state when to choose this tool over alternatives like 'update_subscription' or 'delete_subscription', nor does it mention prerequisites or exclusions, leaving usage context partially implied.

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