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 implies a mutation operation ('Update') and specifies the HTTP method (PUT), which is helpful. However, it lacks details on permissions, side effects (e.g., whether this affects active subscriptions), error handling, or response format. The description adds some behavioral context but leaves 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 front-loaded with the core purpose, followed by essential details (HTTP method, required/optional fields, exclusions) in a single, efficient sentence. Every part earns its place without redundancy, making it easy to parse quickly.

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?

For a mutation tool with no annotations and no output schema, the description is adequate but incomplete. It covers the what and how (updating billing address via PUT) but lacks behavioral context (e.g., auth needs, rate limits, response structure). Given the complexity of payment operations, more guidance on usage and outcomes would be beneficial.

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 fully documents all parameters and nested properties. The description repeats some parameter details (e.g., required fields, optional street2) but does not add significant meaning beyond the schema, such as explaining the purpose of 'countryCode' or format constraints. 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 specific action ('Update a payment method's billing address') and resource ('gateway-agnostic'), distinguishing it from siblings like 'update_customer_address' or 'update_customer_payment_method' (which might handle different fields). It explicitly mentions what is being updated (billing address only) and what is excluded (no payment or gateway-specific fields).

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 clear context for when to use this tool: to update billing address fields for a payment method, with explicit exclusions ('No payment or gateway-specific fields'). However, it does not name specific alternatives (e.g., when to use 'update_customer_address' instead) or mention prerequisites, though the required parameters imply the need for existing customer and payment method IDs.

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