hmda_validate_uli

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

Annotations already set readOnlyHint=true, so the description's burden is lower. It adds that the tool verifies the check digit and returns a validity boolean, which is meaningful behavioral context beyond the annotation. No side effects are mentioned, but the read-only nature is sufficient for this operation.

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 three short sentences, each adding value: the action, the output, and the purpose. It is front-loaded with the main verb and contains no redundant or unnecessary 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, read-only validation tool with no output schema, the description fully covers what it does, what it returns, and why it would be used. No additional details about error handling or algorithms are needed for this simple operation.

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?

Schema coverage is 100% and the parameter description already explains the structure ('Full ULI to validate (loan ID + 2-digit check digit)'). The description adds that the tool 'verifies its check digit,' which reinforces the parameter's role but does not introduce extra semantic detail beyond the schema. Baseline 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 opens with 'Validate a Universal Loan Identifier (ULI) by verifying its check digit,' which is a specific verb ('validate'), a clear resource (ULI), and the method (check digit verification). It also states the return value ('Returns whether the ULI is valid or invalid'), fully distinguishing it from siblings like hmda_check_digit that generate check digits.

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 does not explicitly contrast with alternatives, but 'Used for HMDA reporting compliance verification' implies the intended context. There is no explicit when-to-use or when-not-to-use guidance, though the tool's simplicity makes it fairly obvious. The sibling list includes hmda_check_digit, and the description does not clarify the difference.

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