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

Annotations already establish readOnlyHint and openWorldHint, and the description adds the critical behavioral fact that the tool no longer produces live data but returns an archive notice. It also discloses the fallback behavior when the date is omitted. It stops short of describing freshness/pagination behavior.

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?

The ARCHIVED status is front-loaded, which is the most important information. The middle enumeration of returned artifacts is longer than strictly necessary and partly duplicates what the output schema already covers, but every sentence is still informative.

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 the return-shape listing is redundant but harmless. The archive status, date semantics, and format are all present, leaving nothing an agent needs in order to avoid misusing this tool or to call it 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 coverage is 100% for the single date parameter, so the baseline would be 3. The description goes beyond the schema by explaining the omitted-date semantics ('today's slate or the next available matchday') and the YYYY-MM-DD format, adding real invocation value.

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+resource ('Get the daily World Cup 2026 matchday market slate') and enumerates the contents returned (closest match market, strongest favorite, draw-risk watch, winner board, share-card SVG, JSON/markdown links). The ARCHIVED prefix immediately separates it from live-market siblings like get_world_cup_odds and get_world_cup_brief.

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?

The date-omission rule is explicit ('omit it for today's slate or the next available matchday'), and the ARCHIVED notice implicitly signals this is not for live data. However, it never names a sibling to use instead for current matchday data, so the when-not-to-use guidance is only implied.

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