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

Annotations already signal read-only and idempotent behavior. The description adds meaningful behavioral detail: it computes federal tax using 2026 tables, sizes 72(t) payments with the real IRS calculation, checks ACA marketplace subsidy lines, and returns all three strategies unless one is selected. This goes beyond the annotations and helps an agent understand what the tool actually calculates.

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 three sentences of dense, purposeful prose. The first sentence defines scope and strategies, the second details the calculation mechanics, and the third states the output behavior. Every sentence contributes, and the structure is front-loaded with the most important purpose 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?

For a complex 16-parameter tool with no output schema, the description gives a strong overview of inputs, calculations, and output selection. It does not detail the exact return shape, but it states that each year's spending, tax, conversions, 72(t) sizes, and ACA subsidy lines are computed, and that all three strategies are returned unless one is chosen. This is sufficient guidance for most calling scenarios, with a small gap around return formatting.

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?

The input schema already documents all 16 parameters with 100% coverage. The description reinforces the meaning of the strategy parameter by explaining that all three strategies are returned unless one is chosen, but it does not add substantial new meaning beyond the schema for the individual parameters. This matches the baseline for high schema coverage.

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's purpose: planning how an early retiree funds the gap between leaving work and age 59.5, comparing three named strategies. It is specific about the resource ('bridge to 59 1/2') and distinguishes itself from single-strategy sibling tools like sepp_72t_payment or roth_conversion_cost by covering multi-year, multi-strategy planning.

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 establishes clear context: it is for early retirees planning the gap years before 59.5, with either all three strategies or one chosen strategy. It does not explicitly state when not to use it or name alternatives, but the context is specific enough that an agent can infer when this tool is appropriate.

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