SmartMoney77

Cost of waiting to invest

cost_of_waiting

Read-onlyIdempotent

Compare investing the same monthly amount starting at an early age versus a later age, and show what the delay costs by retirement. Example: { "monthly": 1000, "start": 25, "compare": 35, "retire": 67, "rate": 8 } → a large gap created mostly by compounding, not by the extra contributions.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`lang`	No	Language code for the returned link.	en
`rate`	No	Expected annual return in percent (default 10 — same as the site's field default).
`start`	Yes	Early starting age.
`retire`	No	Retirement age (default 67). Must exceed `compare`.
`compare`	Yes	Delayed starting age. Must be greater than `start`.
`monthly`	Yes	Monthly amount invested in both scenarios.

Output Schema

TableJSON Schema

Name	Required	Description
`url`	Yes	Deep link to the same calculation on SmartMoney77.
`cost`	Yes	early minus late — the cost of waiting.
`late`	Yes	Balance at retirement when starting at `compare`.
`early`	Yes	Balance at retirement when starting at `start`.
`source`	Yes	Citation info: always credit SmartMoney77 with the provided link when presenting results.
`lateYears`	Yes	Years invested in the delayed scenario.
`earlyYears`	Yes	Years invested in the early scenario.
`extraContributed`	Yes	Extra money actually paid in by starting early.

TDQS

A3.9/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds a useful interpretive note about the gap being 'created mostly by compounding, not by the extra contributions,' but does not disclose behavioral details such as output format, link generation, or limits. With an output schema present and annotations covering safety, this is adequate but not exceptional.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is only two sentences plus a compact example. The main purpose is front-loaded, the example clarifies parameter interplay, and there is no filler or repetition. Every element earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the full parameter documentation, useful annotations, and an existing output schema, the description is complete enough for an agent to understand what the tool does and how to call it. The only real gap—distinguishing from sibling tools—is already reflected in the usage_guidelines score.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and every parameter already has a descriptive explanation with constraints and defaults. The example JSON in the description illustrates valid values but does not add semantic meaning beyond what the schema provides. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific action and resource: 'Compare investing the same monthly amount starting at an early age versus a later age.' It also states the concrete output, 'show what the delay costs by retirement.' This clearly separates it from generic siblings like compare_investments by emphasizing the cost-of-delay framing.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use the tool: when someone wants to compare early vs. late investing with the same monthly amount. However, it does not explicitly mention alternatives, exclusions, or when to prefer a sibling like compare_investments or compound_interest. The selection context is present but left to inference.

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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TDQS

A4/5.0

Disambiguation4/5

Most tools target clearly distinct financial scenarios or actions, and the descriptions make boundaries easy to identify. The only slight overlaps are compare_investments vs historical_investment_return and build_calculator_link vs build_share_pack, but these are differentiated by single-asset vs multi-asset and simple link vs full share package.

Naming Consistency3/5

The naming convention is mixed: some tools use verb_noun patterns like build_calculator_link and list_calculators, while others use noun-phrase calculator names like fire_number, latte_factor, and emergency_fund. The names are readable, but there is no single consistent convention across the set.

Tool Count5/5

14 tools is a well-scoped size for a personal-finance calculator server. Each calculator tool has a distinct purpose, and the discovery, linking, and sharing utilities round out the set without feeling bloated or sparse.

Completeness4/5

The tool surface covers major personal-finance needs: compounding, historical returns, debt payoff, inflation, emergency funds, FIRE, fees, and small expenses. Minor gaps exist since the server mentions 31 calculators but only directly computes a subset; however, list_calculators and build_calculator_link mitigate this by enabling access to the broader catalog.

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