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

Annotations already declare readOnly and openWorld, and the description adds genuinely new behavior: price per successful call ($0.002 USDC), payment rails (Base, Solana, Arc), and that failed calls are not charged. It omits freshness/caching and any rate-limit behavior, but the cost/charging disclosure is meaningful context beyond annotations.

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?

Front-loads what is returned, then the passing-only constraint, then pricing. Dense but every clause carries information; the field list is long but functional.

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?

Output schema exists so return shape needn't be re-explained, and the cost model is disclosed. What's missing is edge behavior: invalid/out-of-range season handling and data recency for the current season.

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%, and both parameters (limit 1-25, season 2020-2026) are fully documented with defaults in the schema. The description adds no paging semantics (e.g., what happens above 25 passers), 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?

Specific verb and resource: NFL official passing leaders for a regular season, sourced from nfl.com, sorted by passing yards, with an explicit field list. The caveat 'Passing only; other categories are not returned' separates it from other NFL stat tools, though no sibling is named outright.

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?

It states the data scope (regular season, passing only) but gives no explicit when-to-use guidance against adjacent tools like dev_espn_nfl_scoreboard or dev_pro_football_reference, nor what to do outside the 2020-2026 range. Usage must be inferred from the scope sentence.

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