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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety and external-data behavior are covered. The description adds the 24-hour trending window, the Sleeper source and Kalshi price pairing, and the "Market data only" caveat, but says nothing about rate limits, auth needs, or failure modes.

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?

One tightly packed sentence: use-case phrasing first, then data sources, then the parameter-conditioned filtering behavior, then a scoping caveat. Nothing is redundant with the title, and every clause carries 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 simple 4-parameter read tool with no output schema or nesting, the description covers the data source, freshness, enrichment (market prices), and the effect of optional filters. Return shape is only implied (players plus prices), which is the main remaining gap.

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 every parameter (including the limit clamp at 25) is already documented. The description restates the filtered-availability semantics of sleeper_username plus league, but adds little beyond what the schema text already conveys; 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?

States a specific verb/resource combination: Sleeper's most-added players over the last 24 hours paired with Kalshi market prices. "Market data only" frames the scope as pricing rather than league actions, which helps separate it from siblings like my_league or best_available, though no sibling is named directly.

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 quoted user intents ("who is everyone adding off waivers", "trending waiver adds this week") that give concrete trigger conditions, and explains that adding position/username/league narrows to still-available players. No explicit when-not or named alternative, so it stops 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.