game_center_matchmaking_rules_update_instance

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

With no annotations, the description carries the full behavioral burden, yet it only states the HTTP method. PATCH does hint at partial-update semantics, but there is no mention of authentication requirements, whether omitted fields are preserved or cleared, reversibility, or side effects on live matchmaking.

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?

The one sentence is short but wastes space by repeating the identical PATCH path twice in parentheses, and it is not front-loaded with any actual purpose statement.

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?

This is a mutation tool with a nested JSON:API request body, no annotations, and no output schema. A bare endpoint-and-schema pointer leaves the agent without the request envelope details, error behavior, or update semantics it needs to call the tool reliably.

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%, so both the id and body parameters are already documented, and the description correctly points the body at the GameCenterMatchmakingRuleUpdateRequest component. This is a marginal pointer rather than added meaning, 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?

The name plus the PATCH path make it inferable that this partially updates an existing Game Center matchmaking rule. However, the description is essentially a restatement of the tool name in HTTP form and does nothing to distinguish it from siblings like game_center_matchmaking_rules_create_instance or _delete_instance.

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?

There is no guidance on when to use this tool versus create/delete/get variants, no prerequisites, and no note about which rule fields are updatable. The agent is left to infer everything from the operation name.

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