Luno MCP Server

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

The description contradicts the annotations: it describes a listing operation (typically read-only), but annotations indicate destructiveHint=true and readOnlyHint=false, suggesting it modifies data. This inconsistency is a serious issue. No additional behavioral traits (e.g., rate limits, side effects) are disclosed, and the contradiction undermines trust in the tool's definition.

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 at three words, front-loading the core purpose without any wasted text. Every word ('List', 'open', 'orders') contributes directly to understanding the tool's function. There's no redundancy or unnecessary elaboration, making it efficient for quick comprehension.

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 complexity (a listing tool with parameters) and lack of output schema, the description is insufficient. It doesn't explain what 'open' means, the format of returned orders, or how results are structured (e.g., pagination). With annotations that are contradictory and no output schema, the description fails to provide enough context for reliable use, especially for a tool marked as destructive.

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 clear docs for 'limit' and 'pair', so the description adds no parameter semantics beyond what's already in the schema. The description doesn't explain how parameters interact (e.g., if 'pair' filters the open orders) or provide usage examples. With high schema coverage, a baseline score of 3 is appropriate, as the description doesn't compensate but doesn't need to.

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 'List open orders' clearly states the verb ('List') and resource ('open orders'), making the purpose immediately understandable. It distinguishes from siblings like 'create_order' or 'cancel_order' by focusing on listing rather than modifying. However, it doesn't specify what constitutes 'open' orders or differentiate from other listing tools like 'list_trades' beyond the resource type.

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 when to prefer 'list_orders' over 'get_order_book' for order data, or how it relates to 'list_trades' for transaction history. There's no indication of prerequisites, such as needing authentication or specific account status, leaving usage context entirely implicit.

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