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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower. The description adds real context beyond them: the exact section count, the curated top feed inclusion, and the boundary that PressPass headlines are out of scope. No mention of rate limits or auth, hence not 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 sentences, zero waste, and the most decision-relevant facts (what it lists and the 'use before headlines' instruction) are front-loaded ahead of the PressPass caveat.

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 need no explanation, and there are no parameters to document. The description supplies the scope, the sibling relationship, and the exclusion, which is everything an agent needs to call it correctly.

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 by rule; there is nothing for the description to disambiguate. It does clarify what the enumerated sections represent (feeds accepted by foxsports_headlines), which is mildly useful framing.

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 (List) and resource (FOX Sports' 23 official RSS sections), and explicitly ties it to the sibling foxsports_headlines whose accepted sections these are. The count and the inclusion of the curated top feed make the scope concrete and distinguishable from foxsports_article/foxsports_news.

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 a clear prerequisite ('Use this before requesting section headlines') and an explicit exclusion (PressPass is a separate release stream and is not supported). It doesn't name an alternative tool for the same discovery task, but the when-to-use signal is unambiguous.

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