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 does disclose important behavioral context: it is a paid tool costing $0.05 USDC via x402 on Base. That pricing/payment detail is genuinely useful. It does not cover auth requirements, rate limits, or data-source limitations.

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?

A single sentence, front-loaded with the cost/payment method, followed by the core function and its output. No 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?

The description explains the return values (what happened at 5/10/20 sessions later), which helps since there is no output schema. But for a 3-parameter tool with 0% schema coverage and no annotations, the undefined parameters leave gaps an agent needs filled.

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 0% across 3 parameters (symbol, window, universe). The description vaguely implies 'window' via 'latest window' but explains nothing about symbol, the window format, or the self/pair enum values. It fails to compensate for the low 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?

States a specific verb and resource: find past windows whose daily return shape best matches the latest window, then report outcomes at 5/10/20 sessions. Clear what it does. It does not differentiate itself from sibling tools like mirror_projection or quant_snapshot, which appear related.

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?

Usage is implied by the description ('best matches the latest window'), so the agent can infer this is a historical-analog lookup. However, there is no explicit when-to-use versus siblings, no exclusions, and no prerequisites mentioned.

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