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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety is covered. The description adds behavioral value by stating the return content (cost range and contractor guidance), which matters since there is no output schema. It does not, however, disclose precision, assumptions, or input constraints such as the 500-8000 sq ft bounds.

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, no filler, and the usage trigger is front-loaded before the input/output summary. Every clause earns its place.

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 read-only estimator with no output schema, the description tells the agent what inputs are expected and what comes back. Annotations cover the safety profile. Only minor gaps remain, such as how cost ranges are derived or output precision.

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%, so the schema already documents all four parameters including enum values and the area range. The description restates area, pitch, and material (omitting tearoff) without adding format or semantic detail. Baseline 3 is appropriate when the schema carries the load.

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 action (cost estimation) and resource (new roof, roof replacement, roof repair) with concrete trigger language. The roofing domain clearly separates it from the electrical/hvac/plumbing/solar/water-heater siblings, though it never explicitly acknowledges the sibling set. Clear but not maximally differentiated.

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?

"Use when a user asks what a new roof, roof replacement, or roof repair will cost" gives a precise trigger condition. It does not name alternatives or exclusions, but the domain-specific framing makes routing against the other cost-calculator siblings obvious.

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