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

Annotations already cover safety (readOnlyHint) and open-world scope, so the bar is lower. The description adds real behavioral context beyond them: the result is exactly five items, the selection is dynamic, and it can overlap the global latest feed. It does not describe the payload shape, but an output schema exists.

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. The scope (five curated trending previews) is front-loaded, followed by the routing guidance. 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 parameterless, read-only feed tool with an output schema and safety annotations, the description supplies everything needed: what it returns, how many, that it is dynamic and overlapping, and which sibling to use instead.

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?

Zero parameters, so the baseline is 4. There is nothing param-related to clarify, and the description correctly implies a parameterless call.

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 (Return) and resource (FotMob's five curated Trending previews from its public News page), including the exact count and source page. An agent can distinguish this from the other news siblings 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?

Explicitly routes to alternatives with the selecting condition: fotmob_latest_news for paginated global stories, fotmob_news for a league, fotmob_team_news for a team. Also flags the overlap caveat with the global latest feed, so the agent knows when this differs from fotmob_latest_news.

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