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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds valuable context beyond those: it explicitly states it does not access BetterOff customer data, does not change page or account state, and does not provide personalized financial advice. These are important behavioral traits for an educational tool and are not fully captured by the annotations.

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 sentences, with the core characterization 'Read-only educational calculator' front-loaded. It efficiently covers purpose, key inputs, and behavioral boundaries with no redundancy or wasted words.

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?

With an output schema available (as indicated) and full parameter documentation, the description is sufficiently complete. It clearly explains what the tool does, its scope, and its limitations. The only minor omission is guidance on how to interpret the result, but the output schema likely covers that. Overall, it is well-rounded for a tool of this complexity.

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?

All 10 parameters have schema descriptions (100% coverage), so the schema already explains each input. The description mentions several key inputs (annual expenses, withdrawal rate, current savings, monthly investment, return assumptions) but adds no new semantic detail beyond what the schema provides. Baseline of 3 is appropriate given full schema coverage.

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 is a read-only educational calculator that estimates a financial independence target from listed inputs. It specifies the verb (estimates), the resource (financial independence target), and distinguishes it from sibling calculators by focusing on FIRE, making its purpose 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 context that it is educational and read-only, and explicitly states it does not provide personalized financial advice or access customer data, which serves as an exclusion. However, it does not compare this tool to sibling calculators (e.g., calc_retirement) or state when to prefer this over alternatives, so usage guidance is mostly implicit.

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