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

Annotations declare readOnlyHint=true and openWorldHint=true; the description earns credit by explaining the open-world behavior concretely (live LTL carrier quote, residential delivery with liftgate) and by setting expectations that the result is a ballpark confirmed by a designer, not a binding price. It does not disclose latency, failure modes, or what the response object looks like, keeping it short of 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?

Two sentences, purpose front-loaded, then the zip_code conditional, then the caveat about designer confirmation. Each sentence carries information, though the freight parenthetical is dense and could be trimmed without loss.

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 an 11-parameter estimator with no output schema, the description covers purpose, the optional freight branch, and that the returned figure is provisional. The main residual gap is that it does not characterize the shape of the returned range/total, but the phrasing 'price range ... and a total' gives 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?

Schema coverage is 91%, so the schema already documents parameters well, including the reach-in vs walk-in wall/dimension split and the package tiers. The description adds only marginal meaning, mainly reinforcing the zip_code freight behavior; it adds nothing about how reach-in widths versus wall_a/b/c should be supplied or what happens when measurements are missing.

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 verb and resource — a ballpark price range for a custom reach-in or walk-in closet — and grounds it in a reference implementation ('same formula as the estimator on pclosets.com/quote'), which tells the agent this is the cheap pre-quote path. It does not explicitly name the sibling request_quote as the escalation, so differentiation from that sibling is only implied.

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 zip_code conditional is spelled out clearly: supply it to get a live freight quote and total, omit it and shipping is quoted with the order. However, there is no explicit statement of when to prefer this over request_quote or how_to_measure, and no when-not guidance — usage is inferable but not stated.

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