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

Annotations already cover readOnly, idempotent, closed-world and non-destructive behavior, yet the description adds real context beyond them: the operation is 'pure arithmetic, no network or model', the output is a range rounded to the nearest $100, and it returns two dated reference cards with sources. It does not discuss error handling for out-of-range inputs, which keeps it from a 5.

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 purpose is front-loaded, but the middle sentence is garbled ('with no published typical figure, two separate dated reference cards and sources') and the no-line-items point is restated across sentences 2 and 3. Roughly a third of the text is redundant or unclear phrasing.

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?

With no output schema, the description carries the return-value burden and does so: it states the shape (a rounded range), the provenance (dated reference cards and sources) and the key limitation (no line items or labor/material split). Inputs, output and behavior are all covered, leaving only edge-case behavior unstated.

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% — the enum bands, area bounds (20–1,000 sq ft) and the length/width exclusivity rule are all fully documented in the schema. The description only loosely maps 'finishes' onto the scope enum and adds no syntax or format detail beyond what is already structured, 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?

The opening sentence gives a precise verb and resource ('Estimate a kitchen remodel budget') and names the inputs ('kitchen size and finishes'). Within a sibling set full of *_cost calculators (driveway_cost, flooring_cost, roof_replacement_cost), the kitchen-remodel domain makes the selection unambiguous without needing to open the 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?

There is no explicit when-to-use statement or named alternative, but the description implies its role as a planning-stage estimator ('national planning estimate') and supplies a negative constraint: it will not give line items or a labor/material split. That implicit scoping is more than nothing but falls short of explicit routing guidance.

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