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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It effectively does so by explaining carry-forward behavior (`effectiveFrom`, `carriedForward: true`), change events with percentage moves, and the inclusion of source URL and content hash for auditability. This goes well beyond a basic operation description.

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 a single dense paragraph that front-loads the primary purpose and then flows into usage details and audit features. Every sentence contributes meaningful information without redundancy or fluff, achieving a high information-to-word ratio.

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 there is no output schema and no annotations, the description is remarkably complete. It covers the main query modes, edge cases (such as unchanged prices), and the nature of the response (including fields like `effectiveFrom`, `carriedForward`, source URL, and content hash). An agent can confidently select and invoke the tool based on this description alone.

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 83%, which sets a baseline of 3. The description adds meaningful semantics beyond the schema: it explains that `asOf` carries forward the previous price if unchanged, that `from`/`to` returns percentage changes, and that `province` empty lists coverage. While not every parameter gets such depth (e.g., `includeDistricts`), the added value is substantial.

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's function: retrieving petrol, diesel, and heating-oil pump prices for all 81 Turkish provinces, with support for past-dated prices. It uses a specific verb ('prices for...') and resource ('81 Turkish provinces'), and its focus on fuel prices distinguishes it from the sibling tools (e.g., email verification, invoice parsing).

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 provides concrete usage scenarios: using `asOf` to get the price on a specific date, using `from`/`to` to retrieve change events, and leaving `province` empty to list coverage. It gives clear context on when to use different parameter combinations, but it does not explicitly state when not to use the tool or mention alternatives (though no direct siblings exist).

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