TCMB exchange rates

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that: the authority backing the data, the 'indicative' (non-tradable) nature of the rates, the 1996 coverage floor, and the non-obvious fallback behavior for non-business days.

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?

Two dense sentences with no filler; the core identity is front-loaded and the fallback caveat follows as a natural qualifier.

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?

For a two-optional-parameter read tool with no output schema, the description covers source, quote direction, default behavior, historical range, and edge-case date resolution. Only the response shape (per-currency rows, rate fields) is left implicit, which is a minor gap.

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 baseline is 3; the description goes further by explaining that the date parameter implicitly supports historical lookups back to 1996 and that out-of-bulletin dates resolve to the previous bulletin. It also clarifies the rate direction (TRY per unit), which the schema does not state.

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?

States a specific verb+resource ('exchange rates'), the issuing authority (TCMB), and the quote convention ('TRY per unit'), which immediately separates it from the sibling convert_currency, which computes conversions rather than retrieving official bulletins.

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?

Gives clear operating context: latest bulletin by default, any past date since 1996, and the weekend/holiday fallback rule. It does not explicitly name convert_currency as the alternative for arithmetic conversion, so the routing guidance is strong but not complete.

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