Luno MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate destructiveHint=true, idempotentHint=false, and readOnlyHint=false, which the description aligns with by implying a mutation ('cancel'). The description adds value by specifying the action, but doesn't elaborate on behavioral aspects like cancellation effects, permissions needed, or error conditions beyond what annotations provide.

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 extremely concise with a single sentence 'Cancel an order', which is front-loaded and wastes no words. It efficiently conveys the core purpose without unnecessary elaboration.

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 destructive nature (destructiveHint=true), lack of output schema, and no annotations covering rate limits or auth needs, the description is incomplete. It doesn't address what happens upon cancellation, return values, or error handling, leaving gaps for a mutation tool.

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?

The input schema has 100% description coverage, with 'order_id' clearly documented. The description doesn't add any parameter details beyond the schema, such as format examples or constraints, so it meets the baseline for high schema coverage without extra value.

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 'Cancel an order' clearly states the action (cancel) and target (order), which is a specific verb+resource combination. However, it doesn't differentiate from sibling tools like 'list_orders' or 'get_transaction' that might involve order operations, leaving the purpose somewhat vague in context.

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 (e.g., order must exist, be in a cancellable state), exclusions, or refer to sibling tools like 'create_order' or 'list_orders' for context, offering minimal usage direction.

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