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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine substance beyond that: the full-draw ordering (qualifying first, final last), the per-round stat set (seeds, frames/legs/sets won, best of, three-dart averages) and the sport-conditional field (century breaks for snooker only), which tells the agent what to expect in the response for each sport.

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?

A single dense sentence with no filler, and the primary identification ('a snooker or darts tournament with its whole draw') is front-loaded before the field inventory. The semicolon-separated clause for the sport-specific field is efficient, though the sentence fragment style makes the tool's action slightly less immediate.

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 carries the return-value burden and does so well by listing what a caller gets back per round and per sport. What remains thin is the operational side: no verb framing, no failure/edge behavior for an unknown tournament id, and no note on whether live or upcoming events are included. For a two-parameter read tool, that is a minor gap rather than a blocking one.

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 both the sport enum values and the tournament_id provenance are already documented in the schema, giving a baseline of 3. The description contributes only indirectly, by showing that 'sport' changes the output shape (three-dart averages for darts, century breaks for snooker), and adds no format guidance for the id itself.

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?

The description names the resource precisely ('a snooker or darts tournament with its whole draw') and enumerates the payload fields, so an agent can tell this is the single-tournament detail tool rather than the list tool get_snooker_darts_tournaments or get_snooker_darts_player. However, it is a noun phrase with no verb, so it describes the returned entity rather than explicitly stating the retrieval action, and it never names the sibling it contrasts with.

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?

There is no explicit when-to-use or when-not-to-use statement; the description only implies usage by describing the full draw payload. The one routing clue ('from get_snooker_darts_tournaments') lives in the input schema rather than the description, so the agent must assemble the call sequence itself. Usage is inferable but not stated.

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