Digikala Plus plans

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

Annotations already declare this as a safe, idempotent, open-world read. The description adds genuinely new behavioral context: the meaning of 'jet' (same-day Tehran/Karaj) and 'fresh' (supermarket), and the caveat that exact shipping fees only appear at checkout.

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?

Front-loaded with the core action, then the usage cue and caveats in two tight sentences. No filler, though the parenthetical detail about jet/fresh adds length that could be trimmed if space were at a premium.

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 zero parameters and an output schema present, the description does not need to explain return values; it covers purpose, benefits, and the checkout-fee caveat. Sufficient for an agent to call it correctly, with only minor room for extra routing detail.

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 per the rubric the baseline is 4. There is nothing further for the description to disambiguate on the parameter side.

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 ('List Digikala Plus membership plans') plus the returned content (price in Toman and benefits). No sibling tool covers Plus memberships, so it is clearly distinguishable from the search/category/product siblings.

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?

'Use when shipping cost matters' gives a concrete triggering condition and explains why (free deliveries per month). It stops short of naming alternatives or when-not-to-use cases, so it is strong context without full routing guidance.

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