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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the full safety profile is covered externally. The description adds the computation's basis (assets vs liabilities) but no permissions, rounding, edge-case, or validation behavior; the return-shape sentence largely duplicates what the output schema provides.

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?

Two short sentences, purpose first, no filler. The return-value clause is somewhat redundant given the output schema exists, keeping it just short of a 5.

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?

For a two-number, deterministic, read-only calculator with full schema coverage, complete annotations, and an output schema, the description covers purpose, inputs, and outputs. Only the definition of debt_ratio_pct (presumably liabilities/assets × 100) is left unstated, which is a minor gap.

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% and both parameters (assets_total, liabilities_total) are fully documented with type, minimum, and unit. The description's 'from assets and liabilities' merely restates the two required fields and adds no semantics such as whether values are gross/net or non-negative-only behavior.

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?

States a specific verb (calculate) and resource (net worth, debt ratio) plus the inputs used (assets and liabilities). It is clear in isolation, but with hundreds of sibling 'calculate_*' tools it makes no attempt to distinguish itself from near-neighbors like calculate_debt_to_income, calculate_net_worth-adjacent finance calculators, or calculate_debt_capacity beyond a pointer to list_bundles.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites, and no exclusions. 'See list_bundles for related finance-universal calculators' is a discovery breadcrumb, not selection guidance — an agent still cannot tell why it would pick this over calculate_debt_to_income or calculate_net_worth-style siblings.

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