netintel_iban_validate

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

With no annotations, the description carries the full behavioral burden and does reasonably well: it declares offline operation, determinism, immediacy, no upstream calls (implying no auth, network, or rate limits), the ~80-country coverage envelope, and notably the error semantics — an invalid IBAN returns 'valid:false' rather than throwing. The trailing truncation leaves the return payload only partially 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?

A single front-loaded sentence with an em-dash enumeration; the verb and resource come first and the differentiating traits (offline, deterministic, fast) follow. The list of checks is dense but each item earns its place. Only the truncation prevents a 5.

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 one-parameter, no-annotation tool, the description covers purpose, scope, safety profile, and even the negative-result contract. With no output schema, it should ideally spell out the full return shape (extracted bank/branch, formatted IBAN), which it only gestures at before cutting off.

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?

One required parameter at 0% schema coverage, so the schema contributes nothing beyond the name 'iban'. The description makes clear the input is an IBAN to be validated but adds no format guidance (spaces, lowercase, country prefix, length limits), which is the main remaining ambiguity. Adequate but not compensating for the coverage gap.

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?

States a specific verb+resource ('Validate any IBAN') and immediately enumerates the substance of the validation: mod-97 check digits, per-country structure, bank/branch extraction, pretty formatting. It also scopes coverage ('~80 countries'), so an agent knows exactly what it gets. No sibling tool validates IBANs, so no in-family confusion is possible.

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?

Usage context is implied rather than stated: 'offline ... deterministic, instant, no upstream' tells the agent this is a zero-dependency local check and therefore safe to call freely, which is useful selection signal. However, there is no explicit when-to-use/when-not framing or named alternative, so guidance is only implied.

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