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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world behavior. The description adds meaningful behavioral context beyond that: it returns no allocation to hold and does not recommend, predict, or calculate tax, which helps set expectations for a read-only analytical tool.

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 front-loaded with the core procedure and then lists typical questions and limits. It is somewhat dense and the typical-questions list is long, but every sentence contributes useful selection or scope information.

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 six-parameter analytical tool with an output schema and full annotation coverage, the description supplies enough context about purpose, usage, and limits. It does not need to explain return values because an output schema exists, though it could say more about what the out-of-sample comparison reports.

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 parameter meanings are already well documented. The description still adds conceptual value by explaining the walk-forward mechanic: fitting on years before each date maps to train_years, holding on unseen prices maps to step_months, and comparison with the held portfolio maps to holdings.

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 analytical procedure: fit on prior years, hold out-of-sample, repeat, and compare optimized refits against the held portfolio and equal weights. It also explicitly distinguishes the tool from allocation-selection by saying it is not for choosing weights and returns no allocation to hold.

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 clear typical questions that indicate when to use the tool, such as testing whether an optimizer would have beaten a portfolio or whether rebalancing to an optimized mix helps. It also states a useful exclusion: only for that question, not for choosing weights or tax advice. It does not name specific sibling alternatives, so it falls short of a 5.

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