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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the tool is a safe read. The description adds transparency about the batch response shape ({ results, errors }) and lists the exact fields returned, which enriches the behavioral model 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?

The description is a single paragraph that front-loads the main purpose and lists many fields. It is slightly verbose but every sentence earns its place by providing useful information. Could be trimmed slightly 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?

Given the tool's simple read-only nature, the presence of a sibling list tool, and no output schema, the description comprehensively covers what is returned (detailed fields), the batch response format, and the HTTP method. No gaps remain for an agent to correctly invoke and interpret results.

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 0%, but the description adds meaning by specifying that loan_ids should be an array (1-50) of strings, implying they are loan IDs. While it doesn't detail ID format, the context and constraint are sufficient for correct invocation.

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, specifying the HTTP method and path (GET /loans/:loanId). It lists the specific fields returned (interestRates, charges, etc.) and distinguishes itself from the sibling openfinance_list_loans by stating '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?

The description explicitly says to use this tool after openfinance_list_loans for deep-diving, and provides usage constraints: pass loan_ids as an array of 1-50 items. This gives clear when-to-use and practical guidance.

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