iban_checkValidate an IBAN by ISO 13616 structure and MOD-97-10 checksum (offline, no bank lookup).
| Name | Required | Description | Default |
|---|---|---|---|
| iban | Yes | IBAN to validate; spaces allowed. |
| Name | Required | Description | Default |
|---|---|---|---|
| tool | No | ||
| scope | No | ||
| valid | Yes | ||
| reason | Yes | ||
| country | No | ||
| normalized | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already communicate read-only and idempotent behavior, so the description's job is lighter. It adds valuable behavioral context by disclosing that validation is offline, does not perform bank lookup, and is limited to format and checksum rules—important because agents might otherwise expect registry or bank verification.
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 a single, front-loaded sentence with no filler. Every element—the validation standard, checksum algorithm, and offline/no-lookup caveat—adds meaningful 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 validator with an output schema and rich annotations, the description covers all essential behavioral aspects: what it validates, how it validates, and what it does not do (bank lookup). The output schema handles return-value details, so nothing needed for correct invocation is missing.
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 fully documents the only parameter, 'iban', including that spaces are allowed. The description goes beyond the schema by explaining the exact validation standard (ISO 13616 and MOD-97-10), which helps the agent understand how the input will be interpreted and validated.
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 verb 'Validate' and the resource 'IBAN', and precisely specifies the validation method: 'ISO 13616 structure and MOD-97-10 checksum'. It also distinguishes itself from bank lookup tools by adding 'offline, no bank lookup', making its scope immediately clear among siblings like luhn_check and vat_mod97_check.
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 phrase 'offline, no bank lookup' clearly signals when this tool is appropriate: for structural and checksum validation only, not for bank account verification or lookups. It does not explicitly name alternative tools, but the context is clear enough for an agent to choose it correctly.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct identifier type or data source: every checksum validation is for a specific standard (IBAN, LEI, VAT, etc.), and the on-chain and rental tools are clearly separate domains. There is no ambiguity between tools; even similar-sounding checks like 'luhn_check' and 'ean13_check' are distinct algorithms with explicit descriptions.
Most validation tools follow a 'X_check' pattern (iban_check, swift_bic_check, ein_format_check), but others deviate: 'company_number_format' uses a noun_noun structure, 'block_info' is noun_noun, and 'batch_validate' and 'context_distill' use verbs. While the pattern is not uniform, the names are readable and the convention is understandable, just not fully consistent.
With 28 tools, this server exceeds the typical 3-15 well-scoped range and even the 16-25 heavy range. The server covers multiple unrelated domains (identifier validation, blockchain queries, rental fraud, text processing), which inflates the count. While each tool is individually justified, the overall surface feels overly broad for a single MCP server.
For each sub-domain, coverage is strong: identifier validation includes a wide range of international standards, on-chain queries cover balances, activity, and settlement history, and rental tools provide risk, verdict, and deposit guard. Minor gaps exist (e.g., no country-specific tax IDs beyond what's listed, no transaction history for arbitrary tokens), but the visible coverage is comprehensive for the stated purposes.