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

With no annotations present, the description carries the full burden of behavioral disclosure. It does disclose at least one meaningful behavior: 'Missing inputs fall back to their documented defaults.' However, it does not state whether the tool is read-only, what side effects exist, or what the output/return value contains.

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 short, but the first sentence contains a duplication ('calculator calculator') and a confusing run-on list that is not clearly structured. The second sentence is useful, but overall the description is not well-organized or front-loaded in a meaningful way.

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?

This is a 5-parameter tool with no output schema and no annotations. The description does not explain what the calculator returns or how the semicolon-listed items ('Solar panels installed', 'Home battery installed', etc.) relate to inputs or outputs. An agent would need schema details to invoke it correctly, and even then the tool's result format remains unclear.

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 five parameters. The description only adds a general note about defaults, which reinforces rather than extends parameter understanding. It does not define roles for the semicolon-listed items relative to the parameters.

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 opens with a specific verb and resource ('Run the Arizona solar cost calculator') that clearly identifies what the tool does. The redundant 'calculator calculator' is a minor quality issue, and the trailing semicolon list hints at outputs without explicit labeling, but the core purpose remains unambiguous.

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 gives no explicit direction on when to use this tool versus sibling tools like calculator_describe or submit_enquiry. Usage is only implied through the tool's name and title, not stated in the description.

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