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

Annotations already cover readOnly/idempotent/non-destructive, so the bar is lower, and the description still adds real substance: overall*/total* include Weak ratings that are never published, and pre-cutoff dates are backtest data. That is behavior an agent could not infer from annotations or schema. It does not say what happens with no date filters, so 4.

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 tight sentences, front-loaded with the resource definition before the reading instructions. The field-heavy middle clause is dense but each detail carries weight; nothing is redundant.

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With no output schema, the description must explain returns, and it names the key published fields and the unpublished ones. For a 4-optional-param read tool with full annotation coverage this is nearly sufficient; the only gap is default behavior when no date range is supplied.

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 baseline is 3; the description earns above that by tying `tier` values to specific output fields (premiumHitRate, goodPicks for Premium; marginalPicks for Standard) and by giving the semantic cutoff for `from`. It adds no guidance on `to` or `league` beyond the schema.

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 resource — the settled record of the model's picks — with a clear scope (settled, filtered). It is distinguishable from siblings like daily_board or games, though it never explicitly contrasts itself with them, so a 4 rather than 5.

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?

Gives concrete usage context: 'Dates before 2026-04-03 are a backtest; use from=2026-04-03 for live picks only' tells the agent exactly how to scope a live query. It does not name alternative tools or state when-not to use it, so it stops short of 5.

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