game_center_activity_images_get_instance

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

No annotations are provided, so the description carries the full disclosure burden, and it discloses nothing beyond the URL. It says nothing about permissions, caching, pagination, or whether a missing id errors versus returns empty.

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 parenthetical exactly repeats the preceding path text, which is pure waste rather than economy. There is no front-loaded purpose statement because there is no prose purpose at all.

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 annotations and no output schema, the description should at least explain what the returned image resource represents and what the sparse-field options control. It leaves that entire burden to the schema and a raw URL.

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 required id and the optional sparse fields parameter are documented in the schema itself. The description adds nothing, but the baseline for full coverage is 3.

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 is a bare restatement of the HTTP method and path, duplicated verbatim in parentheses. It conveys only that this is a GET of a gameCenterActivityImages resource by id, which is already fully implied by the tool name. It gives no differentiation from the many sibling get_instance tools.

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?

No when-to-use, prerequisites, or alternatives are stated. The agent gets no indication of when this specific resource fetch is appropriate versus, say, the localizations or versions image relationships in the sibling list.

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