validate_gstin

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

With no annotations, the description transparently details the tool's operations: validation of format and checksum, extraction of state and PAN, and return of state name. It does not cover error handling or rate limits, but the core behavior is well-described.

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 concise with two sentences, front-loading the purpose and key details. Every sentence adds value without redundancy.

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?

Given the single parameter, presence of an output schema, and clear description of validation logic, the description is nearly complete. It could briefly mention what happens on invalid input, but overall it is adequate.

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%, and the description adds meaning by specifying the parameter is a 15-character GSTIN with an example '29AABCT1332L1ZS', clarifying the format beyond the schema's description.

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 it validates Indian GSTIN, including format and checksum, and extracts state and PAN. It distinguishes itself from sibling tools like validate_pan by focusing on GSTIN.

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 does not provide explicit guidance on when to use this tool versus alternatives, such as validate_pan or lookup_pincode. The context of sibling tools suggests distinct purposes, but the description lacks proactive usage advice.

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