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

Annotations already signal read-only, idempotent, and non-destructive behavior. The description adds meaningful constraints beyond that: the index series must be official and never approximated, and all dates must be interpreted as Jalali. This is useful behavioral context not present in the schema.

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?

Three short sentences with no filler. The most decision-relevant facts—legal basis, official-data warning, and Jalali dates—are front-loaded and every sentence earns its place.

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 calculation tool with fully documented parameters, the description is sufficient to select and invoke it correctly. It does not describe the return value, but no output schema exists and the computed damage amount is a natural output, so this 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 description coverage is 100%, so all six parameters are already documented. The description does not add parameter-level meaning beyond the schema; it only reinforces the Jalali date convention already stated in the schema.

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 ('Calculate'), the exact legal basis (art. 522 ق.آ.د.م), the data source (Central Bank price index), and the date system (Jalali). This clearly distinguishes it from sibling calculation tools like calculate_diyeh or calculate_lawyer_fee.

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 clearly implies when to use this tool: for late-payment damages under Art. 522 using the official Central Bank index. It does not explicitly name alternatives or exclusions, but the legal-article anchor gives enough context to route an agent correctly among the calculate_* siblings.

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