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

With no annotations provided, the description carries the full burden of behavioral disclosure. It communicates that the tool returns rates across term lengths for a fixed profile, implying a read-only operation. However, it omits details such as the return format (e.g., per $1,000 coverage, monthly vs annual rates) and whether all term lengths are always included. This is adequate but not rich.

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 exactly two sentences: the first states the precise inputs and outputs, and the second gives a practical use case. There is no filler or redundant information; every word serves a purpose.

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 simple 4-parameter tool with no output schema, the description covers the core purpose and a common use case. It lacks explicit return-format details, which would be helpful for an agent to know what to expect, and it does not address edge cases like invalid inputs. Overall, it is sufficiently complete for tool selection but has minor gaps.

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 input schema already provides descriptions for 75% of parameters, including valid values for health_class and the note to call list_options for coverage. The description adds little beyond restating the parameter list, though it emphasizes the 'fixed profile' requirement. Given high schema coverage, a score of 3 is appropriate.

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 function: 'Given a fixed profile ... returns rates across all available term lengths.' It explicitly lists the term lengths (10, 15, 20, 25, 30 years) and provides a concrete use case ('should I get a 20 or 30 year term?'). This distinguishes it from sibling tools like compare_health_classes and query_rates by focusing specifically on term-length comparison.

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 clear context on when to use the tool: when comparing term lengths for a fixed profile. The example question 'should I get a 20 or 30 year term?' makes this practical. It does not explicitly mention when not to use it or name alternative tools, but the specific phrasing and sibling tool names imply a distinct role.

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