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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds operational facts the annotations do not: no API key required and no quota consumed, which matters for an agent deciding whether it is cheap to call. It does not describe the shape of the returned list, which is the remaining gap.

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 short sentences, front-loaded with what is listed and followed by the operational caveats. The Turkish and English versions are near-duplicates rather than a single tight statement, which is mild redundancy, but each sentence still carries distinct information (purpose, then no-key/no-quota).

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 zero-parameter, read-only lookup with no output schema, the definition covers purpose, downstream use, and cost/auth behavior. The only missing piece is any hint about the returned value's format (e.g. a flat array of code strings), which would fully close the loop given there is no output schema.

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 tool takes zero parameters, so the baseline is 4 and there is nothing for the schema to document. The description still adds value by explaining that the returned codes are the accepted inputs for get_prices' source argument, linking the output to a downstream parameter.

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 and resource ("lists the price source codes") and explicitly scopes it as "accepted by get_prices", which ties it directly to a named sibling. An agent can distinguish it from get_prices, get_price_history and calculate_value without opening any 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?

The parenthetical "(get_prices için `source`)" makes the intended use clear: call this to discover valid values for get_prices' source argument. It stops short of an explicit "call this before/only when you need a source code" instruction, and names no exclusion cases, but the usage context is unambiguous.

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