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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds a valuable caveat—'Uncalibrated heuristic, not a survey'—which helps an agent calibrate trust in the result, and it notes the role of optional assumptions.

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, front-loaded with the core operation and inputs, followed by a caveat and a usage trigger. No filler or redundant repetition of the schema.

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 an output schema present and safety annotations already covering idempotence and read-only behavior, the description completes the picture: what it estimates, its reliability, and when to use it. The nested assumptions object is referenced, leaving schema details to do the remaining work.

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 low at 20%, but the description compensates by mapping the main parameters to real-world meaning: value, age, and unit count, plus optional assumptions. It does not flesh out the nested assumption fields, but the schema documents annualRent separately.

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 names a specific operation (estimate), a concrete resource (annual maintenance reserve in OMR), and the key inputs (value, age, unit count). It also distinguishes itself from analysis/inspection tools by calling itself an uncalibrated heuristic, not a survey.

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?

It gives an explicit trigger: use when an agent needs an annual maintenance reserve estimate for a property. It also provides a when-not by stating 'not an actual inspection,' though it does not name a specific alternative sibling tool.

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