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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds a genuinely useful interpretive note that WATCH calls are reported separately, but says nothing about data freshness, grading lag, or how the 'current model era' is bounded.

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?

Two sentences, trigger phrases front-loaded ahead of the content inventory, no filler. The second sentence is dense with enumerated metrics but each item is a distinct return field, so the length is earned rather than padded.

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?

No output schema exists, so the description carries the return-value burden and does so reasonably: it names the metrics (W-L, net P/L, 95% range, model era, backtest) and the separate WATCH reporting. It could still clarify ordering, per-engine grouping, or grading recency for full completeness.

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% and the lane parameter's allowed values are fully listed in the schema, so the schema already does the heavy lifting. The description's engine list (bitcoin, gold, silver, oil, weather, NHL, POTD, NFL) merely mirrors the schema's lane values, adding no new semantics such as default behavior or slug format.

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/resource combination — every graded signal per engine plus the daily editorial call — and enumerates exactly what metrics come back (W-L, net P/L, 95% win-rate range, model era, NFL backtest). No sibling covers accuracy/track-record reporting, so an agent can route here unambiguously.

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?

Opens with explicit trigger phrasings ('how accurate is your model', 'what's your track record'), which is clear when-to-use guidance. It does not name an alternative or an exclusion case, so it stops short of the top tier.

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