savings_rate

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

With no annotations, the description carries full burden. It discloses that the ratio is an estimate due to mismatched time windows (YTD income vs trailing spend) and instructs reading the caveats array. This adequately conveys the estimation trait, though it doesn't list specific caveats.

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 sentences with no waste: the first defines the metric, the second captures the estimation nuance and directs attention to caveats. Front-loaded definition, though slightly more structuring around usage could improve scannability.

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 zero-parameter, no-annotation tool, the description effectively communicates purpose, estimation nature, and the caveats array. It does not specify return format or units, but the mention of caveats implies output structure. Complete enough for correct invocation.

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 tool accepts no parameters, so the description correctly adds nothing about parameter behavior. The baseline for zero-param tools is 4, and the description sufficiently explains the tool's computation without needing parameter details.

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 states a specific computation: 'share of earnings being kept' combining payroll savings and post-spending survival. It clearly distinguishes from sibling tools like income_summary or expenses_spend by focusing on the ratio, not raw amounts.

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 implies the tool is for estimating savings rate and explicitly warns to read caveats before quoting. It does not name alternatives or exclusions, but the context (zero parameters, focused purpose) makes when-to-use clear from its definition.

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