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

Annotations already declare readOnly=true, openWorld=false, destructive=false, so the safety profile is covered. The description adds value beyond them by disclosing the freshness semantics ('latest weekly') and, since there is no output schema, that the response includes club count and a league page URL.

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 with no filler; what the tool returns is front-loaded before the input hint. Every clause carries information.

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 read with no output schema, the description is nearly sufficient: it names the returned contents and the input source. It could say slightly more about what the strength value itself represents (units/scale), which is the only remaining gap.

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 0%, so the description must carry the load; it does by identifying the parameter as a league slug and, crucially, stating that it comes from the resolve tool. It leaves the slug character format to the schema's regex, which is acceptable.

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 ('Returns one league's latest weekly 442ball league strength') with clear scope ('latest weekly') and names the returned fields (club count, league page URL). The word 'strength' plus 'latest weekly' cleanly separates it from siblings like league_index, league_runs, and rankings.

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?

'Takes the league slug from resolve' explicitly routes the agent to the sibling that produces the required input, which is the main usage decision here. It does not state when to prefer this over league_runs/league_index, so it stops short of full alternative routing.

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