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

With no annotations provided, the description must disclose behavioral traits. It mentions that the calculation 'Includes vacancy and management,' which adds context about the model's assumptions. However, it does not describe the return format, whether defaults are applied, or any limitations. The description is not misleading but leaves out significant behavioral details.

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 two short sentences with no redundancy. The purpose is front-loaded, and the key metrics are listed efficiently. Every word earns its place, and it is appropriately sized for the tool's simplicity.

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?

Given the tool has 6 parameters and no output schema, the description should clarify return behavior and assumptions. It lists outputs but does not specify the format or whether they are provided together. It also omits mention of defaults for vacancyRate and managementRate, though these are in the schema. For an agent to call it correctly, the description is adequate but not comprehensive.

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 100%, so the baseline is 3. The description does not add meaning beyond the schema; it mentions vacancy and management, which are already documented with defaults. It does not clarify relationships between parameters or provide examples, so it adds no additional semantic value.

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 states the tool's purpose: calculating rental property ROI with specific metrics (cap rate, cash-on-cash return, NOI, annual cash flow). It specifies the resource (rental property) and distinct outputs, making it readily distinguishable from generic calculate_roi or other finance calculators.

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 usage for rental property ROI but does not explicitly state when to use it over alternatives like calculate_roi or calculate_mortgage. There is no mention of exclusions or selection criteria, though the focus on rental property provides some implicit context.

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