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

No annotations are provided, so the description carries the full burden. It discloses key behavioral aspects: outputs are in today's dollars (implying inflation adjustment) and include a withdrawal-rate-based income estimate. However, it does not state assumptions (e.g., compounding frequency, tax treatment), limitations, or how the gap is defined. This is moderate transparency but leaves several behavioral details unspoken.

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 a single, front-loaded sentence that immediately communicates the tool's core purpose and key outputs. It is efficient with no filler words. It could slightly improve by mentioning optionality or assumptions, but for its length it is well-structured.

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 9 parameters, no output schema, and no annotations, the description must do more to enable correct usage. It lists output variables but does not define 'gap', explain the inflation adjustment methodology, or mention that some parameters are optional. An agent might call this tool without knowing whether Social Security or other income is required, or what the default withdrawal rate is. The description is insufficient for a tool with 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?

Schema description coverage is 100%, so the baseline is 3. The description does not add any parameter-specific meaning beyond listing outputs; it does not explain how parameters like annualReturnPct or withdrawalRatePct interact, nor does it clarify optional parameters (withdrawalRatePct, otherRetirementIncome). The description adds no semantic value over the schema, so a 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 computes a retirement projection with specific outputs: projected nest egg, sustainable income, gap, and required monthly contribution. It uses a specific verb ('calculate' implied) and resource (retirement), and while it doesn't explicitly name sibling tools, it is distinct enough from the many other calculators in the sibling list.

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?

There is no guidance on when to use this tool versus alternatives such as calculate_compound_interest or compare_401k_vs_roth. No exclusions, no conditions, and no mention of scenarios where a different tool would be more appropriate. The agent is left to infer usage solely from the tool name and sibling list.

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