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

Annotations already cover the safety profile (read-only, idempotent, non-destructive). The description adds useful behavioral context by specifying the governing legal articles, the inclusion of حجب نقصانی reductions, and the reliability rationale, but it does not disclose return format or assumptions about debts/wills. For a computation tool with strong annotations, this is adequate though not exhaustive.

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?

Two tightly written sentences: the first carries the operational scope and legal citation, the second gives a concise usage directive. There is no filler and the most important facts are 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?

The tool is legally complex and has no output schema, but the description provides strong legal anchoring and an explicit reliability/usage directive. The main omission is the return format, though it is reasonably inferable from 'inheritance shares'; optional-parameter defaults are also not stated, but the schema covers parameter meanings well.

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 the schema already documents all eight parameters. The description does not add per-parameter details beyond the legal framing; even the mention of حجب نقصانی is already echoed in the sibling_count parameter description. Baseline 3 is appropriate.

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') with a precise resource ('Iranian inheritance shares') and a legal basis (قانون مدنی arts. 862–949), and explicitly names the حجب نقصانی reduction rules. This clearly distinguishes it from sibling calculators such as 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?

Gives clear guidance to use this tool for any Iranian inheritance-share calculation, and even says 'always use this tool' because hand computation is unreliable. It does not explicitly list when-not-to-use or name alternative calculators, but the domain is sharply bounded.

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