game_center_groups_update_instance

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: not whether the update is partial vs full replacement, what happens to omitted fields, permission requirements, or reversibility. It merely defers to an external OpenAPI schema, which is a pointer rather than disclosure.

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?

It is short, but the endpoint is redundantly duplicated in the parenthetical and no plain-language purpose is front-loaded. Size is fine; the structure wastes its one sentence on a repeated route string.

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 mutation tool with a nested, opaque JSON:API body object, no annotations, and no output schema, the definition is far from complete. An agent cannot determine what fields are settable or what a successful update returns without leaving the tool definition entirely.

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% for both parameters, and the schema already states the body shape reference, so the description adds no parameter meaning beyond it. Baseline 3 applies when the schema does the heavy lifting.

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 only restates the HTTP route (PATCH /v1/gameCenterGroups/{id}), which is already encoded in the tool name game_center_groups_update_instance. It never says in plain language what updating a Game Center group means or what can be changed, so an agent gets no more than it could infer from the name.

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 about when to use this tool versus the sibling game_center_groups_create_instance, game_center_groups_get_instance, or game_center_groups_delete_instance. Nothing indicates prerequisites (existing group id) or that the resource must already exist.

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