Get thumbnail performance

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

With no annotations provided, the description carries full burden here. It discloses the read-only nature ('Read'), the exact performance metrics returned, and the live/inactive dimension. It doesn't address edge cases like missing games or permission issues, but for a read tool the behavioral surface is well-conveyed.

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?

Three sentences, no wasted words. The verb-resource is front-loaded, the metrics are listed compactly, and an example query anchors the purpose. Every sentence earns its place.

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 read-only tool with 3 well-documented params, no output schema, and no annotations, the description covers the key ground: what metrics are returned, the live/inactive split, and the intended use case. It could be more explicit about the return value structure, but since no output schema exists, the description does a solid job with the available context.

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 the baseline is 3. The description does add a small amount of color by explaining the live vs inactive split (correlating with includeInactive) and framing the performance metrics, but it doesn't contribute materially new param semantics that the schema's descriptions lack.

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 uses a clear verb-resource pair ('Read a game's thumbnails and how they are performing'), enumerates specific metrics (QPTR, impressions, qualified plays, average playtime), and the live/inactive split. It differentiates itself from analytics-focused siblings like get_qptr_trend and get_thumbnail_momentum by framing itself as the general performance checklist for a game's thumbnails.

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?

Includes a concrete example question ('how are the thumbnails doing on <game>') that signals when to invoke this tool. It provides clear context for when it applies, but there are no explicit exclusions or named alternatives (e.g., 'for a single metric trend, use get_qptr_trend'), so it doesn't earn a 5.

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