estimate_interest

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

No annotations are provided, so the description must disclose behavioral traits. It only mentions the API key requirement but does not specify whether the operation is read-only, what the return value format is, or any side effects. The word 'estimate' implies a calculation, but the description lacks explicit statements about non-mutation or expected output, leaving significant behavioral gaps.

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 extremely concise, consisting of two sentences with no filler. It front-loads the purpose and then adds the authentication requirement. While very short, it could have included more critical usage or behavior details without becoming verbose, but as written it is appropriately sized for the content it conveys.

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 and no annotations, the description should explain what the tool returns and how it differs from similar tools like get_accrued_interest. It does neither. It lacks information about the response format, units of the interest estimate, and when to prefer this tool over others. This leaves an agent with insufficient context to fully utilize the tool correctly.

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 description coverage is 100%, with each parameter (principal, duration_days, interest_rate_bps) having a clear description including units. The tool description adds no additional meaning beyond the schema, such as calculation specifics or relationship between parameters, so it does not enhance what the schema already 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's function: 'Estimate total interest for given loan terms.' This specifies the verb (estimate), the resource (total interest), and the scope (given loan terms), distinguishing it from related tools like get_accrued_interest which deals with actual accrued interest on existing loans. No ambiguity in what the tool does.

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 implies usage for hypothetical loan term calculations by saying 'given loan terms,' but it does not explicitly state when to use this tool over alternatives (e.g., get_accrued_interest) or any exclusions. The only additional guidance is the API key requirement, which is more about authentication than usage context.

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