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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true. Description adds beyond annotations: explains that test includes primary residence equity and pension by default, returns specific outputs (verdict, breakdown, routing). 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?

Description is lengthy but well-organized: starts with purpose, then test details, then output, then use cases. Every sentence adds value, though some details (e.g., 'Calculated by Fox Davidson...') could be moved to a 'provider' field. Still, it is efficient and front-loaded.

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, so description must explain return values. It states 'Returns verdict, per-applicant test breakdown, joint household aggregate (if joint), and a routing recommendation including the relevant UK private bank list.' This is complete for a qualification check. Additional logic about pension and primary residence inclusion is also covered.

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 100%, so baseline is 3. Description adds meaning beyond schema: explains how net assets are calculated (including pension, primary residence), what the test thresholds are, and that joint application aggregates. This adds significant context 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?

Description clearly states tool checks UK mortgage applicant HNW qualification under FCA MCOB 3A, with specific thresholds (income >= GBP 300k or net assets >= GBP 3m). It distinguishes from sibling tools (bridging loan calculator, stamp duty calculator) which are different 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?

Explicitly lists when to use: when user asks about HNW mortgage qualification, MCOB 3A, income/net assets test, private bank mortgages, large loans. Does not provide explicit when-not-to-use or alternatives, but the context is clear and sufficient.

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