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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false, idempotentHint=false), so the bar is lower. The description adds the ordering convention ("newest first") and the content scope, which is useful, but the trailing fragments "Facts only. Insights feature." are terse and ambiguous rather than informative, and return format/volume is unaddressed.

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?

It is appropriately short and leads with the content description, but the compressed clause-piling and the dangling fragments "Facts only. Insights feature." reduce readability and feel like leftover notes rather than earning their 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?

For a read-only listing tool with no output schema, the description does the work of describing return content (facts, story elements, sentence forms) and ordering, which compensates for the absent output schema. It stops short of describing result volume or pagination, but is close to complete.

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 all five parameters (lang, since, sport, league_id, min_importance) are already fully documented in the schema. The description only echoes the language list already present in the schema, adding no new parameter meaning beyond the baseline.

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 states a specific resource (facts about finished matches in a league) and enumerates the concrete content it returns: match story, comebacks, late winners, red cards, runs, table places and zones. It implicitly distinguishes itself from raw siblings like get_matches or get_standings by framing itself as a curated fact/story feed, though it never names those siblings explicitly.

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 an explicit usage cue: "Use for 'what happened in this league today'" plus a scope marker ("Facts only"). It gives clear context for when to reach for this tool but offers no when-not guidance and names no alternative tools for adjacent needs.

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