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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuine non-obvious behavior: the when=today case retains last night's cards that started under 6 hours ago, and forecast/market data is only present 'when known'. The citation instruction ('Cite the url of each card or bout') also discloses a usage requirement not visible in structured fields.

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 the resource and scope, then a compact field list, then usage triggers, then the caveat and citation rule. Slightly dense with the inline field enumeration, but 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?

An output schema exists, so return values need no explanation, and the description still covers grouping, optional market data, and the citation obligation. Nothing critical to correct invocation is missing for a three-optional-parameter read tool.

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 the baseline is 3, but the description earns a bump by quantifying the 'today' carry-over window (cards that started under 6 hours ago), which the schema's vague 'cards still running from last night' does not specify. Country and division semantics are left entirely to 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 and scope ('Upcoming professional boxing cards worldwide, grouped by card') and enumerates what each card contains (date, start_utc, venue, promoter, broadcasters, bouts with records, division, rounds, title, forecast). The 'upcoming' framing cleanly separates it from boxing_results and next_fight without ambiguity.

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 user-question triggers ('who is fighting tonight / this weekend', 'what boxing is on'), which map usage to intent well. It stops short of naming alternatives (e.g., boxing_results for past cards, next_fight for a single fighter), so the routing is clear but not exhaustive.

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