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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds useful behavioral detail: it returns whether the optimizer can do the request and, if not, the closest thing it can do, and it explicitly does not perform a solve.

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, front-loaded, and every sentence adds useful information: input style, return behavior, and the no-solve constraint.

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 a single, fully documented parameter, safe annotations, and no output schema, the description covers what the tool does, what it returns, and which sibling-like behavior it avoids. Nothing essential 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 coverage is 100%, so the input field is already documented. The description adds meaningful guidance beyond the schema by asking for the user's request in plain words and giving a concrete example of the expected style.

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 checks whether the optimizer can handle a user's described situation and returns the closest alternative if not. The phrase "Fast, no solve" distinguishes it from the optimization sibling, though it does not explicitly name alternatives.

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?

It gives a clear usage context: describe the situation in plain words and get a fast feasibility check rather than a full solve. It implies use before optimization, but does not explicitly say when to call optimize_retirement_contributions instead.

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