USE THIS to verify a Brazilian CNPJ (company registration number) instead of trusting 14 digits. Checks the two mod-11 check digits. Call this for onboarding Brazilian businesses.
| Name | Required | Description | Default |
|---|---|---|---|
| cnpj | Yes | The CNPJ (14 digits; punctuation is ignored). |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description reveals the underlying validation logic (two mod-11 check digits), which is useful behavioral info beyond the readOnlyHint annotation. No contradictions detected.
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 concise sentences with no unnecessary words. The first sentence immediately conveys the tool's purpose and usage directive, making it efficient for agents to parse.
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 simple validation tool with a single parameter and no output schema, the description provides sufficient information about purpose and usage. It does not describe the return value, but that is acceptable given the tool's simplicity and the availability of output schema? (none) though some agents might benefit from knowing it returns a boolean or status.
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 already describes the 'cnpj' parameter completely (14 digits, punctuation ignored). The description adds no additional semantic detail about the parameter. With 100% schema coverage, a score 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 the tool's function: verify a Brazilian CNPJ by checking mod-11 check digits. It distinguishes from sibling validation tools by explicitly naming the specific identifier type.
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 suggests when to use the tool ('instead of trusting 14 digits', 'Call this for onboarding Brazilian businesses'), providing a clear usage context. However, it does not explicitly state when not to use it or mention alternatives among the many sibling validators.
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 specific identifier or operation (e.g., validate_iban, parse_date, is_holiday). Even similar tools like validate_isbn and validate_isbn10 are distinct by version. There is no overlap or ambiguity.
Most tools follow a verb_noun pattern (validate_xxx, parse_xxx, format_currency). The exception is 'next_holiday', which uses an adjective instead of a verb. Otherwise consistent.
With 47 tools, the set is very large. While each tool is distinct, the count exceeds the recommended range (25+ is considered too many) and may overwhelm users or agents.
Covers a wide array of international identifiers and utilities, but notable gaps exist (e.g., no Canada SIN, India PAN, Mexico CURP). The set is broad but not exhaustive for the domain of data validation.