get_cover_image

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

With no annotations provided, the description carries the full disclosure burden and does meaningful work: it reveals the CDN-first download strategy with fallback to the GitHub Contents API, and the write-to-local-file-then-return behavior. It stops short of stating what happens when both sources fail, but the disclosed flow is substantive.

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 terse sentences with no filler: purpose, download strategy, and return value each occupy one sentence. The most important fact (what the tool does) 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?

For a 5-parameter tool with no annotations and no output schema, the description covers the core contract: source, fallback order, write destination, and return payload (path and size). The only notable gap is error behavior when both CDN and GitHub API fail, which neither the schema nor the description specifies.

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 the baseline applies — every parameter (game_id, library, use_cdn, token_gh, output_path) is already described in the schema. The description reinforces the {game_id}.webp naming link to game_id and explains why token_gh is conditional, but adds little beyond what the schema's parameter descriptions already state.

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 states a specific verb and resource: downloading the cover image for a given game, with the exact file pattern {game_id}.webp. It also names the deliverable (local file plus returned path and size), which cleanly distinguishes it from the sibling upload_cover_image.

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?

The description implies when to use the tool: whenever a cover image needs to be fetched from the remote library. However, it never names an alternative or states when not to use it, so the agent must infer selection from the purpose alone rather than from explicit routing.

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