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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds two genuinely useful behavioral facts beyond the schema: the result includes an 'upcoming matches' availability flag, and the call is 'Free' (no credit/quota cost). It still says nothing about caching, ordering, or return shape beyond that flag.

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?

Eleven words with the resource front-loaded and the two key facts (upcoming-match flag, free) trailing. It is composed of fragments rather than sentences, which is terse but unambiguous, and nothing is redundant.

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 no parameters and no output schema, the description carries the burden of describing the response and does so at a high level (sports plus an upcoming-match flag). It does not mention whether names or IDs are returned, but for a zero-arg discovery list that omission is minor.

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 schema contributes nothing to explain and the baseline is 4. The description correctly wastes no words on parameters (there are none) and spends its budget on the return-side semantics instead.

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 the resource (sports) and the returned attribute (whether each has upcoming matches), which is more specific than the bare name. It doesn't explicitly contrast itself with siblings like find_leagues or find_teams, but the scope (all sports, global) is inferable from the fragment.

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?

No when-to-use guidance, no prerequisites, and no alternative named. An agent must infer that this is a discovery/entry-point call rather than a filtered query, with nothing in the text to confirm or deny that.

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