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

Annotations already mark this as a non-read-only, destructive operation, and the description goes well beyond them: it discloses the authorisation requirement (organisers only), the state transition that opens voting, the returned vote link, the replace-not-append semantics of repeat calls, and the hard immutability boundary once voting closes. The 'confirm with the user first' instruction is exactly the kind of caution an agent cannot infer from structured fields.

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?

Four sentences, front-loaded with the purpose, then the lifecycle, then the safety instruction. Every sentence carries a distinct behavioural fact (authorisation, voting trigger, idempotency, immutability) with no repetition or filler.

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 naming the vote link that the first call returns. For a three-parameter mutation tool with a state machine behind it, all the information an agent needs to call it safely and correctly is present.

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%, so scoreA, scoreB and matchId are already documented (including that matchId comes from pick_teams or get_squad). The description adds no scoring format or validation detail beyond the schema, so the baseline of 3 applies.

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 and resource ('Save a match's final score') plus the two scoping conditions that define it: organisers only, and only after kick-off. This clearly separates it from setup-time siblings like set_game, make_fixtures and pick_teams without needing the schema opened.

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 an explicit prerequisite (organisers only, after kick-off) and spells out the full call lifecycle: first call opens voting and returns the vote link, repeat calls correct the score without touching voting, and calls after voting closes are rejected. It also instructs the agent to confirm the score with the user before calling. No alternative tool is needed, and the exclusions are stated rather than implied.

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