get_tickers

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

Annotations already provide readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. The description adds that the endpoint is public and no auth required, and explains the fields included in each ticker (last trade price, best bid, best ask, 24h volume), providing beyond-annotation context.

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 two sentences, front-loaded with the core functionality, and each sentence adds specific value: first states purpose, second covers output, use case, and alternative. No wasted words.

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 that an output schema exists and annotations are provided, the description covers input parameter usage, output fields, comparison with sibling, and authentication requirements, making it fully complete for an AI agent.

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% for the only parameter 'pair'. The description elaborates on the format ('comma-separated list'), gives an example, and clarifies behavior when omitted ('return every supported pair'), adding 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 tool lists the latest tickers for all Luno trading pairs or a subset, using the specific verb 'list' and resource 'tickers'. It distinguishes from the sibling tool get_ticker by noting the use case for multiple vs. single pair.

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 explicitly tells when to use this tool ('survey or compare multiple markets in one call') and when to use the alternative get_ticker ('when you only need a single pair'). It also notes that it is a public endpoint with no auth required.

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