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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real behavior: no solve is performed, the output includes a one-line explanation per field, and the two variants differ substantively (married adds two earners, kids, HSA, two-tier match).

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?

Four short sentences, zero filler, front-loaded with the outcome before the caveat and the parameter detail. Every sentence carries distinct information.

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?

There is no output schema, and the description compensates by describing the return value (a complete example input plus per-field explanations). It could go one step further and name the sequence of calls (this → optimize_retirement_contributions), but for a single-enum helper it is nearly complete.

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 0%, so the description must carry the parameter. It does more than the enum allows: it names the default ('single') and qualitatively expands what 'married' models — two earners, HSA, two-tier match — which the bare enum values cannot convey.

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 and resource: 'Return a complete example input for optimize_retirement_contributions.' It explicitly positions itself against the sibling solver with 'No solve,' so an agent can distinguish the example generator from the optimizer without opening either schema.

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?

'No solve. Edit it to the user's situation' tells the agent what this tool is NOT for and what to do with the output, which is genuine routing guidance. It implies this is a precursor to calling optimize_retirement_contributions but never states the ordering or the condition that should trigger the call.

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