Luno MCP Server

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

The description contradicts the annotations: it describes a read operation ('Get ticker information'), but annotations indicate destructiveHint=true and readOnlyHint=false, suggesting this tool might modify or delete data. This inconsistency is a serious issue, as the agent cannot rely on the description for accurate behavioral cues.

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, efficient sentence that directly states the tool's purpose without any wasted words. It is appropriately sized and front-loaded, making it easy for an agent 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?

Given the contradiction between the description and annotations, and the lack of an output schema, the description is incomplete. It fails to provide reliable behavioral context or clarify the tool's actual effects, leaving significant gaps for the agent to navigate.

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 the 'pair' parameter clearly documented as 'Trading pair (e.g., XBTZAR)'. The description adds no additional meaning beyond this, so it meets the baseline score of 3 where the schema handles 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 verb ('Get') and resource ('ticker information for a trading pair'), making the purpose immediately understandable. However, it doesn't distinguish this tool from its sibling 'get_tickers' (plural), which likely retrieves multiple tickers, leaving some ambiguity about when to use one versus the other.

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 the sibling 'get_tickers' or clarify if this is for single-pair lookups versus bulk operations, nor does it specify any prerequisites or exclusions, leaving the agent to infer usage context.

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