game_center_activity_images_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, yet it discloses nothing: not whether PATCH is a partial or full replacement, not required permissions, not reversibility, not side effects on the associated activity. It only supplies an HTTP verb, which is already implied by the tool name 'update_instance'.

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 single sentence duplicates the path (PATCH /v1/gameCenterActivityImages/{id} appears twice in parentheses), which is pure waste. Brevity here is under-specification rather than conciseness, and no functional purpose 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?

This is a mutation tool with a nested-object body, no annotations, and no output schema, so the description must do heavy lifting. Instead it defers entirely to an external OpenAPI document the agent may not have, leaving update semantics, field constraints, and response behavior wholly unexplained.

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 'id' and 'body' are documented in the schema, establishing the baseline of 3. The description's pointer to components.schemas.GameCenterActivityImageUpdateRequest adds nothing beyond what the body property description already states, and gives no field-level meaning for a nested JSON:API envelope.

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 exposes the HTTP verb and route (PATCH /v1/gameCenterActivityImages/{id}), from which an agent can infer it updates a game center activity image. However, it never states the purpose in functional terms (e.g. 'update an activity image's metadata or upload state'), so it is only implied rather than explained. The route does distinguish it from sibling get/create/delete operations on the same resource, but only by method.

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 when-to-use guidance, no prerequisites (e.g. the image must already exist), and no mention of alternatives like game_center_activity_images_create_instance or the get/delete siblings. The agent gets no signal about when this tool is the correct choice.

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