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

Annotations already declare readOnly, idempotent, non-destructive. Description adds batch behavior and error structure, but no additional side effects, rate limits, or auth details. Adds moderate value beyond annotations.

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?

Description is a single sentence that efficiently conveys purpose, usage context, fields, and batch shape. No wasted words, but could be slightly more structured (e.g., bullet points for fields).

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 no output schema, description lists key return fields (interestRates, charges, etc.) and batch result shape. Adequate for a retrieval tool with annotations covering safety. Minor omission: no error detail beyond {results, errors}.

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 has 0% description coverage; description compensates by explaining loan_ids is an array of strings (1-50 items) and how it's used in batch. Adds meaning beyond schema structure.

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?

Description explicitly states it returns full loan detail by ID, lists specific fields (interestRates, charges, etc.), and distinguishes from sibling openfinance_list_loans by saying 'Use after openfinance_list_loans to deep-dive on a specific contract.'

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?

Provides clear usage context: use after openfinance_list_loans for deep-dive. Specifies batch input (1-50 loan_ids) and output shape ({results, errors}). Lacks explicit when-not-to-use or alternatives, but context is sufficient.

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