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

With annotations declaring readOnly and idempotent behavior, the description adds the exact operational formula (NOI as a percent of property value), which clarifies the calculation beyond the structured metadata. It does not address edge cases like zero property value, but the output schema and simple nature reduce the need.

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 description is a single, front-loaded sentence that defines the concept and formula without any filler or redundancy. Every word 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 two-parameter calculator with an output schema and read-only annotations, the description plus schema fully specifies the calculation. It lacks explicit usage scenarios or edge-case handling, but these are not critical for such a self-contained formula tool.

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 schema already provides 100% description coverage for both parameters. The description adds the relationship between them—'net operating income as a percent of property value'—clarifies the numerator and denominator roles, and indicates the output is a percentage, which goes beyond the schema's simple field labels.

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 clearly defines what the tool computes: capitalization rate as net operating income divided by property value. Though it lacks an explicit verb like 'calculate', the formula makes the tool's function unambiguous and distinct from siblings like gross-rent-multiplier or noi.

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 used to compute cap rate but provides no explicit guidance on when to choose it over alternatives or any exclusions. For a simple formula calculator, this implied usage is acceptable, but it does not meet the standard for a 4.

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