Türkiye IBAN biçim kontrolü

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

Annotations already declare readOnlyHint=true, so the description correctly aligns by stating it does not modify anything. It adds the behavioral detail that it does not verify account existence, which is useful. However, it does not disclose what happens with invalid IBANs (e.g., error vs. boolean return) or the exact output format beyond extracting the bank code, despite having an output schema that might cover this.

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 that add value. It is front-loaded with the core action (mod-97 validation) and the offline exception. The bilingual duplication is a minor inefficiency but not harmful.

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 tool's simplicity (one parameter, read-only, no nested objects) and presence of an output schema, the description covers the essential purpose. The only gap is lack of detail on error handling or return values, but the output schema likely explains the return structure, so what's provided 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?

The schema already describes the 'iban' parameter fully with format and length, so coverage is 100%. The description adds little beyond restating 'TR IBAN' and mentioning spaces are allowed, which is already in the schema. Thus, baseline of 3 is appropriate.

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 performs ISO 13616 mod-97 validation for Turkish IBANs and extracts the 5-digit bank code. While it doesn't explicitly contrast with sibling tools, its purpose is specific and unambiguous among the listed tools, which are unrelated (currency rates, earthquakes, weather, etc.).

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 mentions it is offline and does not verify account existence, implying when to use it (format-only check) versus a tool that would verify account existence. However, it does not explicitly state when to use this over alternatives, as there is no direct sibling for IBAN validation. The context signals (openWorldHint=false) align with the offline claim, but explicit guidance is minimal.

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