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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond that: it promises low latency ('fastest, lowest-latency read') and mentions the plan requirement (FREE plan, no card needed), which are not in annotations. This is meaningful addition without contradiction.

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 concise sentences with no filler. The first sentence establishes the core purpose and a key differentiator (speed). The second provides the usage condition and a plan constraint. Everything earns its place, and the most critical info is front-loaded.

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 single-parameter read with an output schema present, the description covers the essential context: what it does, when to use it, and a plan constraint. It doesn't mention edge cases (e.g., match not found, stale data), but these are typically not required for such a lightweight read and are likely handled by the API response schema. Slightly more detail about the response format could be added, but it's not critical given the output schema exists.

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 schema already provides a thorough description for match_id, including valid sources. Schema description coverage is 100%, so the description adds no extra parameter semantics. It doesn't repeat or enhance the parameter documentation, which is acceptable given the schema's completeness. Baseline of 3 is 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?

The description clearly states the verb and resource: 'Current score for one match' – a specific read operation. It also distinguishes itself from siblings by highlighting 'fastest, lowest-latency read', implying it is the lightweight option compared to tools like get_match or get_match_events. This gives an agent a clear sense of what it does and how it differs.

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 description explicitly says 'Use this when you only need the score and already know the match id', which provides a clear condition for selection. It also notes it works on the FREE plan, which is a practical constraint. It doesn't name alternative tools explicitly, but the 'only need the score' phrasing implicitly steers away from richer tools. This is strong guidance, though not exhaustive.

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