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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds a genuinely non-obvious trait: the provider's delimited text is returned as-is and not converted to JSON, which materially affects how the agent must parse the result. Minor gap: no note on rate limits or auth.

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 tight sentences with zero padding; the primary action and resource lead, followed by the sibling routing in the second sentence. Every clause earns its place.

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 needn't be enumerated, and the description still flags the non-JSON text format. With one fully-documented parameter and annotations covering safety, nothing an agent needs to call this correctly is 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 description coverage is 100% and the schema already documents that id is an eight-character value from a public match URL. The description's 'copied from a match URL' largely restates the schema, adding no format or validation detail beyond it, so baseline 3 applies.

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) plus the exact resource (head-to-head and recent-result data) scoped to a single match id. It explicitly names the sibling tools it is not, so an agent can distinguish it from flashscore_match_stats/info/lineups without opening any schema.

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?

Names three concrete alternatives (flashscore_match_stats, flashscore_match_info, flashscore_match_lineups) with the condition 'for other match details', which routes the agent away from misuse. It stops short of stating a positive when-to-prefer condition beyond the tool name itself, but the routing guidance is clear.

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