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

Annotations already declare readOnly, idempotent, non-destructive and non-open-world, so the safety profile is covered. The description adds value beyond them: result ordering (newest first), the impact-tagging taxonomy, and the "Basic plan and above" entitlement requirement, which annotations cannot express. It stops short of describing pagination or result-size behavior, which keeps it below a 5.

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 compact sentences: the first front-loads what is returned and how it is ordered/tagged, the second handles usage and the alternative. Every clause carries information (return shape, ordering, tags, triggers, sibling, plan tier) with no restatement of the name or 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?

With an output schema present, return values need no explanation; the description still usefully characterizes the headline shape and ordering. Parameters are fully documented in the schema, the sibling alternative and the plan gate are stated, and the player_id ambiguity is handled by pointing to search_players — 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% — every parameter including player_id's "First Last#POS" format, defenses as "#DST", case-insensitivity, and the pointer to search_players is already documented in the schema. The description adds no parameter-level syntax or defaults beyond that, so the 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?

The description states a specific verb and resource ("Returns recent news headlines for one player") plus the ordering (newest first) and the shape of each item (tagged by impact with the four tag values). It also explicitly names the sibling it is not — "for the whole league use get_latest_news" — so an agent can distinguish it without opening either 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?

It gives concrete when-to-use triggers ("any news on X?" and injury or role questions about a specific player) and a clear alternative with its selecting condition (whole league → get_latest_news). The plan requirement ("Basic plan and above") is also stated, so the agent knows an entitlement gate exists before calling.

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