Check an IFSC code's format

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

Annotations already declare readOnly, idempotent, and closed-world behavior, so the safety profile is covered. The description adds real value beyond that by disclosing that bank names are resolved only for well-known codes (partial coverage) and by stating the negative capabilities. It does not say what happens on a malformed input (error vs. a failed-validation result), which is a meaningful gap for a validator.

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 tight sentences: the positive capability with its rule comes first, the limitation second. No filler, no repetition of the title, every clause carries information.

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?

For a single-parameter, no-output-schema validation tool, the description covers what is checked, what extra data (bank name) may come back, and the limits of the result. The only omission is the shape of an invalid-format response, which matters somewhat since no output schema exists.

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 single parameter is documented, so the baseline is 3. The description does add structural meaning beyond the schema by decomposing the code into 4 letters + zero + 6 branch characters, though it leaves a slight inconsistency with the schema's maxLength of 30 versus the stated 11 characters unaddressed.

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 names a specific verb ('Checks the format') and resource (IFSC code) and spells out the validation rule (4 bank letters, a zero, 6 branch characters), so an agent knows exactly what is examined. The IFSC resource is inherently distinct from the sibling validators (GSTIN, PAN, Aadhaar), though no sibling is named explicitly.

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?

Clear scope boundaries are given: it validates format only and explicitly does NOT confirm branch existence or return an address, which steers an agent away from using it as a branch lookup. It stops short of naming an alternative tool to use instead when branch or address data is needed.

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