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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the tool is safe and idempotent. The description adds the batch size limit (1-50) and the error handling shape, which goes beyond annotations. No contradictions.

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 a single, focused paragraph. It lists key returned fields without excessive detail, and every sentence adds value. Slightly longer due to field enumeration but still efficient.

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?

No output schema exists, so the description lists contract detail fields, batch shape, and parameter constraints. For a simple one-parameter tool, this covers the essential information needed for correct invocation.

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 100% required parameters but 0% description coverage. The description compensates by specifying 'Pass `loan_ids` as an array (1-50)' and mentions batch behavior, adding meaning beyond what the schema provides.

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 returns full loan contract detail by ID, lists specific fields returned (interestRates, charges, etc.), and explicitly distinguishes its use from sibling openfinance_list_loans via 'Use after... to deep-dive.'

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 explicit when-to-use: 'Use after openfinance_list_loans to deep-dive on a specific contract.' Also specifies parameter constraints (array of 1-50 IDs) and result shape ({results, errors}).

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