Price history of a phone

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

Annotations already establish that this is a read-only, idempotent, non-destructive, open-world tool. Beyond that, the description adds useful behavioral context: the data source, the specific aggregations returned, the currency unit, and the caveat that shops may quote different variants. It still does not describe data freshness, coverage gaps, or rate limits, but the added context is meaningful.

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 two short paragraphs with the purpose front-loaded and the interpretive guidance following immediately. Every sentence contributes either scope or usage guidance, and there is no redundant wording.

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 simple read-only tool with three fully documented parameters, safety annotations, and no output schema, the description does the remaining work: it explains what the returned price history contains, the unit, and how to interpret the daily lowest figure. Nothing critical for correct invocation appears to be missing.

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 100%, and all three parameters are already documented in the schema, including the product id source, the period enum, and shop_id filtering. The description does not add parameter-specific meaning beyond what the schema provides, so the baseline 3 applies.

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 states a specific verb and resource: getting a phone's shop-price history from Mobile.ir. It also names the returned aggregates (per-shop first/last/min/max and daily lowest price), making the scope clear. It does not explicitly distinguish itself from siblings such as mi_market_prices or mi_shop_prices, so it falls short of a 5.

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 gives a clear use context: answering whether a price is rising, falling or fair, and it advises using the daily lowest rather than a single shop for market trend. It does not explicitly name alternative tools or state when-not-to-use conditions, so it is strong but not a full alternatives-based 5.

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