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

Annotations (readOnlyHint=true, idempotentHint=true, destructiveHint=false) are consistent. The description adds significant behavioral context: ownership-aware stress rates (personal uses 5.5%; ltd uses max of product rate or 5.5%), calculation by a specific broker, and the ICR thresholds used. 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, information-dense paragraph. It front-loads the purpose effectively. While slightly long, every sentence adds value. Could be broken into bullet points for clarity, but overall concise enough.

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?

The description explains inputs and computations but does not describe the output format or structure. Since there is no output schema, this information is missing. However, the tool's functionality is simple and the example uses provide some context. Adequate but incomplete.

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 baseline is 3. The description adds some value by explaining the ownership stress rate difference and reiterating total rent for HMO, but does not significantly deepen understanding beyond the schema descriptions.

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 runs a UK buy-to-let ICR stress test, calculates specific metrics (ICR at product and stress rates, gross yield, max loan at three thresholds), and identifies lender categories. This is a specific verb+resource with clear differentiation from siblings (other property finance calculators).

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 explicit use cases: when a user asks about BTL deal viability, ICR, max loan, or HMO/MUFB qualification. It does not explicitly state when not to use or name alternatives, but the sibling list provides context. Clear context with minor room for improvement.

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