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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: the granularity of the response (per-leg, per-visit) and a specific failure mode (not found for untracked-scoring streamed events and non-darts matches). No auth or rate-limit detail, but the added context is meaningful.

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?

Two sentences, front-loaded with the returned payload and closing with the id requirement and failure conditions. Dense but every clause earns its place; no filler.

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 read-only, single-param tool with a rich output schema present, the description need not explain return values, yet it usefully previews them and covers the not-found edge cases. Nothing an agent needs to call it correctly appears to be missing.

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% and the schema already documents the single id parameter (eight-character Flashscore id from a public match URL). The description only restates 'Pass a match id' without adding format or sourcing detail, so baseline 3 is appropriate.

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 (Fetch) and resource (a Flashscore darts match), and enumerates the distinctive darts-specific payload: leg-by-leg visits, remaining totals, 180/140+ highlights, leg finishes and a statistics comparison. This distinguishes it clearly from sibling flashscore_match_* tools (box score, lineups, stats) that cover other sports.

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?

Gives direct usage ('Pass a match id') and an explicit when-not condition: streamed events without tracked scoring and non-darts matches return not found. That guards the caller against misusing it on other sports. It does not, however, name which sibling to use instead for non-darts matches, so it stops short of full routing guidance.

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