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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so the safety bar is low; the description adds real value by disclosing what comes back (the applicable rule plus its source) and the substantive rule thresholds. It does not say what happens for exports dated before 1 October 2026, leaving a genuine behavioral hole.

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?

A single dense sentence that front-loads the core concept before the parenthetical rule detail. Every clause carries information, though the nested parenthetical costs a little readability.

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 no output schema, the description does well to say the response includes the rule and its source. However, for a rule-driven calculator it omits what the tool does with pre-October-2026 export dates and how the goods/services distinction affects the answer, so an agent cannot fully predict the outcome.

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 coverage is 67% and the schema already documents export_date and currency, so baseline applies. The description contributes indirectly by explaining that the twelve-month window applies when invoiced or settled in rupees, which hints at how currency changes the result, but it never explains the goods/services enum or how kind alters the calculation.

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?

Names a specific domain concept (the last day to realise and repatriate export proceeds under FEMA) and what accompanies the answer (the rule and its source), so an agent can tell it apart from the adjacent services_edf_due_date. The verb is implicit — it never says 'returns the deadline' — but the resource and scope are unambiguous.

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?

No when-to-use or when-not-to-use guidance, and no routing against the closest sibling services_edf_due_date, which an agent could easily confuse this with. The eligibility rule (exports from 1 October 2026) is stated as domain fact but not framed as a precondition for calling the tool.

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