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

With readOnly/idempotent annotations already covering safety, the description still contributes real behavioral context: shares are final once status is locked or played (open Classic matches still move), Classic matches have scoreRecorded false and only home/draw/away, and groups under 20 players are withheld with a reason. That is exactly the kind of edge-case disclosure an agent cannot get from 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-loaded with purpose and lookup method, then return shape, then edge cases; every sentence carries information. It is a dense single paragraph with several parenthetical asides, which costs a little scannability.

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?

No output schema exists, yet the description names the returned fields, explains the group ranking tiers, covers the Classic-vs-National divergence, and documents the withheld-group case. An agent can call this correctly and interpret the response without further documentation.

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 baseline is 3, but the description adds semantics the schema does not: the two lookup keys are alternatives, a partial team name ('Arsenal') is sufficient, and the id format maps to daily/classic match families. It does not say what happens if neither parameter is supplied, which keeps it off a 5.

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: 'The TipMaster expert prediction for one football (soccer) match,' and enumerates the return payload (mostLikelyScore, top 3 exact scores, home/draw/away split by group). It never names a sibling to contrast with, so an agent must infer the boundary with get_consensus or get_expert_picks, but the resource is concrete enough to be actionable.

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 clear invocation context for both lookup paths ('found by team names ... one team name also works) or by id' and notes that near-misses are surfaced via alternatives, which tells the agent how to recover from a failed lookup. It stops short of explicit when-to-use/when-not guidance versus the sibling prediction/consensus tools.

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