hmda_check_digit

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

Annotations declare readOnlyHint=true, and the description does not contradict it. The description adds useful behavioral detail by explaining that the tool appends the two-digit check digit to create a valid ULI, which clarifies the output format beyond what the annotation provides.

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 sentences, each serving a purpose: stating the action, describing the output, and providing the regulatory context. There is no redundancy or fluff.

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 computation with no output schema, the description fully covers input, output behavior, and usage purpose. It explicitly states what the tool does with the input and why it is used, making it self-contained.

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 already covers the parameter with 100% coverage, describing loan_id as 'Loan ID (LEI + institution-assigned loan identifier, without check digit)'. The description only repeats 'from a loan ID' and 'appends' without adding new parameter semantics, so it does not improve on the schema.

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 uses a specific verb ('Generate'), identifies the resource ('ULI check digit'), and defines the input ('loan ID'). It clearly distinguishes itself from sibling hmda_validate_uli, which is for validation rather than generation.

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 states the context ('Used for HMDA reporting compliance') and the action (generating a check digit), which implies when to use the tool. However, it does not explicitly mention alternatives or exclusions, such as 'use hmda_validate_uli to validate an existing ULI.'

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