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

With no annotations, the description carries the full burden. It discloses that the calculation uses the current official rate, that fractions are statutory, and that the return includes the governing article and rate source. This is meaningful behavioral context beyond a generic description, though it does not mention edge cases like unrecognized injuries or handling of haram months.

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 tight sentences: the first states purpose and method, the second gives usage guidance and return value. There is no filler, and the most important information is front-loaded.

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 calculator with 3 parameters and no output schema, the description covers purpose, usage rationale, and return value (amount, article, source). It does not elaborate on error behavior or output structure, but it provides enough for an agent to select and invoke the tool correctly.

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?

All parameters are already described in the input schema (100% coverage), so the baseline is 3. The description adds value by connecting the year parameter to the annual rate change and the injury to statutory fractions, exceeding the baseline with useful context.

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 calculates دیه for bodily injuries using the current official rate and fractions from قانون مجازات اسلامی. The verb 'Calculate' plus the specific resource ('دیه for a bodily injury') distinguishes it from sibling calculators like calculate_delay_penalty or calculate_tax.

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 explicitly instructs 'ALWAYS use this instead of computing دیه yourself' and explains why (annual rate changes, statutory fractions). This provides clear when-to-use guidance, though it does not explicitly exclude or name alternative sibling tools (e.g., lookup_annual_rate) for cases where only a rate is needed.

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