get_ticker

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true. The description adds that it is a public endpoint with no auth required and lists the returned fields (price, bid, ask, volume). This provides useful context beyond annotations, warranting a 4.

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 consists of two concise sentences. The first sentence defines the tool, and the second provides usage guidance. No extraneous words, and the most important information is front-loaded.

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 simplicity (one required parameter, no nested objects, with output schema), the description covers the purpose, when to use, what it returns, and authentication status. Combined with annotations, it is fully complete for an agent to use correctly.

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 coverage is 100%, and the schema already describes the parameter thoroughly (e.g., 'Trading pair using Luno's symbol convention... BTC is automatically rewritten to XBT'). The description does not add further parameter semantics, so baseline 3 is appropriate.

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 gets the latest ticker (last trade price, best bid, best ask, 24h rolling volume) for a single Luno trading pair. It uses specific verbs ('Get the latest ticker') and resource ('Luno trading pair'), and differentiates from siblings like get_tickers and get_order_book.

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 says when to use this tool ('quick price snapshot of one market') and when to use alternatives ('use get_tickers for multiple markets at once, or get_order_book for depth-of-book'). This provides clear recommendations and exclusions.

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