renovation_roi

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

With no annotations, the description carries the full behavioral burden, and it delivers: it discloses the conservative high-cost assumption, the exact ROI formula, the 15% default gate, failure messaging that explains the miss, and the deliberate optionality of arguments to route missing-input refusals as payloads. This exceeds what annotations would typically provide.

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 compact and front-loaded: purpose first, then formula, then failure behavior, then the optional-arguments rationale. Every sentence adds information, and there is no filler or repetition of schema contents.

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 four-parameter tool with no annotations or output schema, the description covers the core invocation context: formula, default threshold, conservative cost stance, failure behavior, and why arguments are optional. It is slightly incomplete on which parameters are minimally needed for a meaningful calculation and on the success-response shape, but an agent can reasonably infer these from the formula.

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 0%, so the description must compensate, and it does meaningfully: it explains total_cost_high as the high-cost denominator, implies rent lift as the difference between target and current monthly rent annualized, and references threshold_pct via the 15% default gate. It does not walk through each parameter by name, but the formula and defaults give enough semantic grounding for correct invocation.

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 names a specific verb ('Check') and a specific resource ('a renovation's rent lift' against an ROI threshold), and the formula makes the exact calculation unambiguous. This is enough to distinguish it from siblings like renovation_estimate or underwrite_run without opening 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?

The description strongly implies when to use the tool—whenever a renovation's rent lift needs to be tested against an ROI gate—and states the default threshold. However, it never explicitly says when not to use it or points to an alternative sibling, leaving comparative selection to the agent's inference.

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