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 states 'Calculate mortgage details,' which implies a calculation but does not mention that it is a read-only operation, whether it uses standard amortization formulas, or any side effects. The description adds minimal behavioral context beyond the input schema.

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 short sentence, which is concise and front-loaded. However, it may be too terse, lacking structure or additional context that would improve clarity without much length. It earns its place but could be slightly expanded for completeness.

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 existence of an output schema (context signal), the description could rely on it for return values. However, the description does not explain what 'mortgage details' means—e.g., monthly payment, total interest, amortization schedule. For a financial calculation tool, this is insufficient for full understanding.

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%, so all parameters are documented in the schema. The description adds no additional meaning beyond the schema. Baseline score of 3 applies because the description does not explain how parameters relate to the calculation (e.g., formula used, relationships between inputs).

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 'Calculate mortgage details' clearly states the action (calculate) and resource (mortgage). It is specific enough to indicate it deals with mortgage-related calculations, but it does not differentiate from sibling tools like 'loan_payment' or 'compound_interest'. The lack of scope (e.g., what details are calculated) slightly reduces 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 provides no guidance on when to use this tool versus alternatives. It does not specify prerequisites, exclusions, or context. Sibling tools like 'loan_payment' or 'simple_interest' may overlap, and the description offers no help in choosing appropriately.

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