lookup_ifsc

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

No annotations are provided, so the description carries the full burden. It discloses that the tool performs a read-only lookup via Razorpay's public API, but omits details like rate limits, authentication, error handling, or data freshness. This is adequate for a simple lookup but lacks depth.

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 concise sentences, front-loaded with the primary action and key data returned. Every word serves a purpose, with no redundancy or fluff.

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 that an output schema exists, the description does not need to detail return values. It sufficiently covers the tool's purpose, data fields, and data source. For a straightforward lookup tool with one parameter, this is complete.

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?

The input schema has 100% coverage with a description for the sole parameter. The tool description adds value by providing context (Indian IFSC, example format 'KKBK0000261') and mentioning the API source, going beyond what the schema alone offers.

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's function: looking up bank, branch, address, and payment rails for an Indian IFSC code. It explicitly differentiates from siblings (PAN, GSTIN, pincode, etc.) by specifying its unique resource.

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 implies usage for querying IFSC codes but does not explicitly state when to use vs. alternatives, nor does it mention exclusions or prerequisites. Siblings are distinct enough that no conflict arises, but some guidance would improve clarity.

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