RMD estimator using the IRS Uniform Lifetime Table
| Name | Required | Description | Default |
|---|---|---|---|
| age | Yes | Age you reach this year (72 to 120). The IRS Uniform Lifetime Table divisor for that age is used. | |
| birthYear | No | Birth year. Adds the SECURE 2.0 RMD start age (73 for 1951-1959, 75 for 1960 or later) and whether an RMD is required yet. | |
| accountBalance | Yes | Account balance on 31 December of the previous year. |
Changes observed during successful MCP inspections.
Input schema / properties / accountBalance / descriptionAdded value: +"Account balance on 31 December of the previous year."Input schema / properties / age / descriptionAdded value: +"Age you reach this year (72 to 120). The IRS Uniform Lifetime Table divisor for that age is used."Input schema / properties / birthYearAdded value: +{
+ "description": "Birth year. Adds the SECURE 2.0 RMD start age (73 for 1951-1959, 75 for 1960 or later) and whether an RMD is required yet.",
+ "type": "number"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds no further behaviour such as that birthYear unlocks SECURE 2.0 start-age logic or that the result is an estimate only — that context lives only in the schema.
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?
A single front-loaded sentence with no filler. It is efficient, though so short that it borders on under-specification given the domain acronym.
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 three-parameter pure calculator with no output schema the description is minimally adequate, but it never says what is returned (an annual RMD dollar amount) or which table row applies, leaving output interpretation to inference.
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 each parameter (age range 72-120, birthYear SECURE 2.0 rules, prior-year-end balance) is documented there. The description adds nothing beyond the schema, so the baseline 3 applies.
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 resource (RMD) and the method (IRS Uniform Lifetime Table), so an agent knows exactly what is computed. It does not differentiate from neighbouring converters_401k / converters_529, and relies on the reader knowing the RMD acronym.
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 statement of when to use this versus other retirement converters, no prerequisites (e.g. must be near or past RMD start age), and no exclusions. Usage must be inferred entirely from the name and schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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