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

Annotations already declare readOnlyHint and openWorldHint, but the description adds real context beyond them: which sportsbooks appear depends on the visitor's region (a material coverage caveat), and the exact payment model — $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls not charged. What it does not disclose is whether odds are live or snapshot, and whether pagination/truncation applies beyond the limit parameter.

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-loaded with the core payload description, then routing, then pricing — a sensible order with no filler sentences. It is dense to the point of run-on, and the example book list plus the truncated sibling phrasing ('odds screens: every;') add a little noise, but each block 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?

An output schema exists so return-shape explanation is unnecessary; the description covers the remaining agent-critical facts — region-dependent book coverage, per-call cost and payment rails, and non-charging on failure. For a 3-parameter read-only odds tool this is complete enough to invoke correctly.

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 team, limit and league are already documented in the schema (including the league enum values and the 1-50 limit range). The description only restates the covered leagues and adds no filtering syntax or format detail beyond what the schema supplies, so the baseline of 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?

Names a specific verb+resource: sportsbook odds scraped from Covers.com odds screens, enumerates the covered leagues (NFL, NBA, MLB, NHL, college, WNBA), and lists exactly what each record contains (Covers game ID, away/home team, kick-off text, per-book American/decimal/fractional prices, market tag). It also explicitly separates itself from dev_vegasinsider and dev_fanduel, so an agent can pick it out of a crowded sports-odds sibling set.

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?

Provides explicit routing to alternatives with the condition that selects them: dev_vegasinsider for VegasInsider lines, dev_fanduel for FanDuel game lines for NFL/NBA/MLB/NHL/WNBA. The league enumeration also implicitly scopes when this tool applies versus the other books.

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