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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine value beyond them by disclosing data freshness ('scores refresh every minute') and what the payload contains (current score and minute), which an agent needs to judge staleness.

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 short sentences with zero filler; the resource and live scope are front-loaded before the freshness note. 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 simple, annotation-covered read with one optional filter and no output schema, the description covers what the agent needs: liveness, payload fields, and refresh cadence. Minor gaps remain around result volume/ordering and whether paused or halftime matches are included, but nothing blocking.

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 coverage is 100% and the single optional league_id is documented as 'Only this league,' so the schema carries the parameter meaning. The description adds nothing about filtering or league scope, making baseline 3 appropriate.

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 resource with a clear temporal scope: matches in progress, returning current score and minute. The phrase 'being played right now' implicitly separates it from get_matches/get_match, though no sibling is named explicitly.

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?

The 'right now' framing implies when to use it (live/in-progress lookups) versus the historical get_matches sibling, but the description never states an explicit condition, prerequisite, or alternative. Usage is inferable but not spelled out.

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