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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds valuable context: it does not change page or account state, does not access BetterOff customer data, and provides no personalized financial advice. This goes beyond the annotations in a meaningful way.

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 three tight sentences with no filler. The first sentence front-loads the core purpose and read-only nature, the second states the calculation, and the third lists the key boundary conditions. Every sentence 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 simple read-only calculator with fully documented parameters, rich annotations, and an output schema, the description covers everything an agent needs: what it computes, what it doesn't do, and its boundaries. No critical operational context is missing.

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%, and each parameter is already documented with its own description in the schema. The description adds a mild interpretive layer by tying 'years to retirement' and 'risk tolerance' to the inputs, but it does not need to add more given the schema's completeness.

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 states a specific verb ('Calculates') and a precise resource ('illustrative portfolio allocation across U.S. stocks, international stocks, bonds, and cash'). It names the two driving inputs (years to retirement and risk tolerance), making it clearly distinguishable from the many sibling calculator tools.

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 establishes clear context: this is an educational, illustrative calculator that uses only caller-supplied public inputs and deliberately avoids personalized advice or access to customer data. It implies when it should be used, though it does not explicitly name alternative tools or state when not to use it.

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