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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: the supported competition set (hot leagues only, e.g. EPL, La Liga, UCL, CSL) and the fact that unsupported competitions return an error rather than empty data — a failure mode an agent must anticipate.

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, front-loaded with the return payload then the usage triggers then coverage limits; each sentence earns its place. Minor redundancy in re-listing league names that the schema already enumerates.

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 output schema, the description compensates by enumerating the returned fields, and it also covers competition coverage and the error case. For a single-parameter read-only tool with its safety profile already in annotations, 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 id examples and points to /llms-full.txt for the full list. The description repeats the hot-league names but adds no syntax, format, or alias guidance beyond the schema, so this is the baseline 3.

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+resource (returns the full standings table for a given league) and enumerates exactly what each row contains: rank, played, W/D/L, goals for/against, goal difference, points, last-five form. This clearly separates it from siblings like get_match_detail and get_live_matches, which are about individual matches rather than league tables.

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?

Gives concrete trigger phrasing for the agent ("英超积分榜", "西甲第几名", "谁是榜首"), which is strong implied usage guidance, and states coverage limits plus the error behavior for unsupported competitions. It stops short of naming an alternative tool or an explicit when-not-to-use condition, so it falls just below the top.

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