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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the live/upcoming scope, which is useful, but the listed return fields largely duplicate what the output schema already provides and it says nothing about pagination, auth, or ordering. Adds modest value over structured fields, hence a 3.

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: the purpose and scope are front-loaded, followed immediately by the disambiguation list. 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?

For a single-parameter list tool with an output schema, full schema coverage, and safety annotations, the description supplies everything an agent needs: resource, scope, and sibling routing. Nothing material 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 single `league` parameter already documents the full set of valid league codes. The description reinforces the routing to fanaticslive_leagues for discovery but adds no format or syntax detail beyond the schema, 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?

States a specific verb and resource ('List live and upcoming Fanatics Live show items for a league') and enumerates the returned payload fields (status, viewers, cover image, host channel/shop). This distinguishes it cleanly from fanaticslive_show, which returns a single show.

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 sibling alternatives with the exact condition that selects each: fanaticslive_leagues to discover the league code, fanaticslive_show for one show, fanaticslive_shop_shows for a shop's shows. An agent can route correctly without opening any other schema.

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