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

Annotations already establish this is a read-only, non-open-world call, so the safety profile is covered. The description adds real behavioral context beyond that: halftime matches are included in the result set, scores and minutes are live, and the cross-midnight coverage gap versus get_matches_by_date is disclosed. It does not discuss rate limits or result ordering/volume caps, which keeps it short of 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?

Three sentences, each with a distinct job: what is returned, when to invoke it, and a subtle coverage caveat. No filler or repetition of the title.

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, no output schema, and minimal annotations, the description still tells the agent what the return contains (matches, live score, minute) and where the tool's scope ends. There is no material gap an agent would need to resolve before calling it.

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?

The tool takes zero parameters, so there is nothing to document and the baseline is 4. The description correctly implies the call is unfiltered and global, consistent with an empty schema.

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 names a specific verb and resource: it returns all matches currently in play (including halftime), with live scores and elapsed minutes. It also implicitly distinguishes itself from the date-based sibling by framing the resource as '此刻正在进行' rather than a calendar day.

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?

It gives explicit trigger phrasing ('现在有什么比赛在踢', '实时比分') and an explicit exclusion case: matches that span midnight, common for European leagues at China time, will NOT appear in get_matches_by_date and must come from this tool. That is a concrete when-to-use/when-not-to-use rule naming the alternative.

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