validate.cusip

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

No annotations are provided, so the description bears the full burden. It discloses the deterministic nature, the use of a weighted check digit, and that it returns validity and check digit. However, it does not explicitly state that the operation is read-only or whether it involves external lookup (e.g., security-master implies a database check). Still, the description is mostly transparent for a simple validation function.

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, consisting of two sentences that cover the core action, input, algorithm, and output. It avoids unnecessary details. However, the phrasing 'Returns valid + check digit. Deterministic security-master validation.' reads slightly fragmented, which slightly detracts from polished structure.

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 simplicity of the tool (one parameter, no output schema), the description is largely complete: it explains what is validated, the algorithm, and what is returned. Minor gaps include ambiguous output format (e.g., how 'valid' is represented) and vague term 'security-master validation' without further explanation. Nonetheless, it provides sufficient context for basic usage.

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 describes the single parameter 'cusip' as '9-character CUSIP.' The description adds meaningful context by specifying it is a US/Canada securities identifier and explaining the mod-10 check digit algorithm, which enriches the agent's understanding of the input format and purpose beyond the schema's basic description.

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 validates a CUSIP identifier, specifies its structure (9-character US/Canada securities identifier), and mentions the algorithm (mod-10 weighted check digit). This explicitly distinguishes it from sibling validation tools for other identifier types like ABA, BIC, etc., providing a specific verb+resource combination.

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 implies usage for CUSIP validation but offers no explicit guidance on when to use this tool versus alternatives. It does not mention when not to use it or point to sibling tools for other identifier formats. While the purpose is clear, the lack of exclusionary or comparative statements limits the agent's ability to choose correctly among many validation siblings.

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