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

Annotations already declare read-only, idempotent and non-destructive, but the description adds substantial context they do not carry: offline operation, check-digit verification only where the algorithm is public (GSTIN), Aadhaar refusal, price per call with x402 payment, and that blank values are rejected uncharged. That is genuinely useful operational disclosure for an agent deciding whether to call and what it will cost.

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?

Information-dense but front-loaded: what it validates, then the special behaviors, then pricing. Every clause carries content, though the single run-on block could be broken up for easier scanning.

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?

No output schema exists, and the description compensates partially by naming the decoded fields (state, PAN holder type, company type) an agent can expect. It stops short of describing the actual response shape (success/failure indication, field names, error format), which would matter for a validation tool.

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 100%, with both parameters and the enum fully documented in the schema, so the description only needs to add marginal meaning. It reiterates auto-detection and the accepted "type:" prefix, which are already in the schema; no extra syntax or normalization rules are supplied beyond that.

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 verb and resource (validate/decode one Indian identifier) and enumerates the exact identifier types covered, so an agent knows precisely what falls inside its scope. The singular scope implicitly separates it from india_id_validate_batch.

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 a concrete usage context ("clean or pre-check form and invoice data") and states the Aadhaar exclusion, which is a real when-not rule. It never names the batch sibling as the alternative for multi-value work, so the routing decision between the two is left to inference.

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