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 genuine behavioral context beyond that: results are scoped per engine, WATCH calls are reported separately from graded calls, and requesting a single lane also surfaces that lane's current model era. It does not discuss data freshness or how far back records go.

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 usage trigger is correctly front-loaded, but the remainder is a packed run-on dense with unexplained jargon (POTD, PLAYs, W-L, 'model era') that forces the reader to decode acronyms mid-sentence. A short bulleted breakdown of what the record contains would read faster than the current comma-chained phrasing.

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 one optional parameter, read-only annotations, and no output schema, the description carries the burden of explaining returns and largely does so: W-L, net P/L, a 95% win-rate range, model era, and the live-versus-backtest split. Remaining gaps are minor — no indication of response structure, ordering, or historical window.

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 single optional lane parameter is fully documented in the schema, including the accepted values and the omit-for-all behavior. The description restates the same engine list and the 'current model era' side effect without adding format or edge-case detail beyond the schema, so the baseline 3 applies.

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 enumerates exactly what is retrieved: every graded signal per engine (bitcoin, gold, silver, oil, weather, NHL), the daily POTD editorial call, and the NFL 2026 live record versus backtest. That makes it clearly a performance-reporting tool rather than a calculator like the sibling tools, though it never uses an explicit verb and never names a sibling to contrast with.

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?

"Use for 'how accurate is your model' and 'what's your track record'" gives concrete user phrasings that should trigger this tool, which is strong context. It stops short of saying when NOT to use it or pointing to an alternative (e.g., use nhl_edge for prospective edge rather than historical record).

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