Turkey Premium Index: what lira buyers pay above the world price, with TRY reference prices from Turkish venues

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

Annotations already cover safety (readOnlyHint=true, openWorldHint=true), so the bar is lower, and the description goes well beyond them by disclosing the return structure: index in bps with dollar/crypto legs, 0-100 score with 50=world price, regime, 24h/7d averages, same-sign streak, five reference prices, per-venue status, spread and depth. It does not state rate limits or freshness beyond 'live', keeping it at 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?

It is front-loaded with the usage trigger before the return description, which is the right order, and every clause carries content. The single long second sentence is dense and slightly run-on for a two-parameter tool, so it is not a clean 5.

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?

With no output schema and a trivial input schema, the description carries the full burden and discharges it: it enumerates the board contents, the scoring scale, the aggregation windows, and the optional history mode. An agent has everything needed to call it and interpret the result.

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%, so both parameters are already documented. The description only restates that passing pair and history_days yields '15-minute history of one pair', which the schema already says, adding no new syntax, defaults, or interaction semantics. 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 names a specific resource (the Turkey Premium Index / lira buyer premium) and its scope, and lists the exact triggers (BTC/ETH/USDT lira prices, USDT/TRY rate, dollar premium, which Turkish venues trade rich/cheap). It implicitly distinguishes itself from the nearby get_coinbase_premium sibling by being Turkey/lira-specific, so an agent can route without opening the schema.

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?

It gives explicit, enumerated when-to-use triggers ('Call this when the user asks about...'), which is strong context. It stops short of naming an alternative or a when-not condition (e.g. use get_coinbase_premium for US premium), so it earns a 4 rather than a 5.

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