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

Annotations already provide readOnlyHint: true, destructiveHint: false, and idempotentHint: true. The description adds the batch response shape ('{ results, errors } batch shape') and confirms it is a read operation. No behavioral contradictions exist, but the description does not add significant behavioral context beyond the annotations and the batch shape.

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 with three sentences. It front-loads the purpose and key details. Every sentence adds value, though a more structured format could improve readability.

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 tool with annotations, the description covers the purpose, usage context, parameter details, and the batch response shape. It is sufficient to guide the agent, though error or edge-case behavior is not addressed.

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 has 0% description coverage, so the description must compensate. It explains the parameter 'loan_ids' as an array of strings and adds a range constraint '1-50'. This provides meaningful guidance beyond the raw 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 clearly states 'Returns full loan contract detail by id' with a specific verb and resource. It distinguishes this tool from its sibling 'openfinance_list_loans' by explicitly stating 'Use after openfinance_list_loans to deep-dive on a specific contract.' The list of returned fields adds specificity.

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 gives clear context: 'Use after openfinance_list_loans to deep-dive on a specific contract.' It also specifies the batch input format 'Pass `loan_ids` as an array (1-50).' However, it does not explicitly state when not to use it or provide alternatives beyond the sibling mentioned.

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