Luno MCP Server

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

The description adds minimal behavioral context beyond annotations. Annotations indicate this is not read-only, is open-world, non-idempotent, and destructive, but the description doesn't explain what 'destructive' means in this context (e.g., does it modify data or have side effects?). It also doesn't mention rate limits, authentication needs, or return format, though annotations cover some safety aspects.

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 a single, clear sentence with no wasted words, making it highly concise and front-loaded. Every word contributes directly to stating the tool's purpose efficiently.

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 low complexity (1 optional parameter) and rich annotations, the description is minimally adequate but incomplete. It lacks output details (no output schema), doesn't explain the destructive hint, and omits sibling differentiation. For a tool with potentially destructive behavior, more context on implications would be helpful.

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?

With 100% schema description coverage, the input schema fully documents the single parameter 'pair'. The description implies listing 'all currency pairs' but doesn't clarify how the optional 'pair' parameter interacts with this (e.g., if it filters results or is required for specific pairs). It adds little semantic value 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 action ('List') and resource ('tickers for all currency pairs'), making the purpose understandable. However, it doesn't distinguish this tool from its sibling 'get_ticker' (singular), which appears to be a similar tool for individual tickers, leaving some ambiguity about when to use each.

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 like 'get_ticker' (for a single ticker) or 'get_markets_info' (which might include ticker data). It lacks explicit when-to-use or when-not-to-use instructions, leaving the agent to infer usage from context alone.

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