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 and effectively discloses key behavioral traits: it explains the partial update mechanism ('fetches the current charge and merges your input'), validation process, and conditional requirements for recurring charges. However, it lacks details on error handling or response format.

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 update mechanism, but becomes verbose with a lengthy list of optional parameters that largely repeat schema information. Some sentences, like the validation note, add value, but the parameter enumeration could be more concise.

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 18 parameters and no annotations or output schema, the description is moderately complete: it covers the update process, partial update behavior, and conditional requirements. However, it lacks details on permissions, side effects, or return values, leaving gaps in contextual understanding.

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 baseline is 3. The description adds some value by clarifying the partial update behavior for chargeTier and listing optional inputs with examples (e.g., 'price as dollars e.g. 22.87 or cents e.g. 2287'), but does not significantly enhance parameter understanding beyond the schema.

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 product rate plan charge') and resource ('product-rateplan-charges/{chargeId}'), distinguishing it from sibling tools like 'create_product_rate_plan_charge' or 'delete_product_rate_plan_charge' by focusing on modification rather than creation or deletion.

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 mentioning partial updates ('You can send only the fields you want to change') and validation ('Validates in MCP before calling the API'), but does not explicitly state when to use this tool versus alternatives like 'update_product_rate_plan' or provide prerequisites beyond the required chargeId.

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