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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the image is auto-resized and that only one display size can be handled per call, but it does not explain prerequisites, whether existing screenshots are replaced, authentication needs, or failure behavior.

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 description is front-loaded with the core action and uses a compact semicolon-separated structure. It is dense but efficient, with no redundant sentences, though the long clause structure makes it slightly harder to scan.

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 no annotations and no output schema, the description covers the main upload constraint and image input alternatives. It remains incomplete because it does not explain broader context such as app/version scoping, permissions, return behavior, or effects on existing screenshots.

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 only 50%, so the description must add meaning. It clarifies screenshot_image_base64 versus screenshot_image_url and the exact-one-display-type rule, but it omits screenshot_file_path, screenshot_display_type as an alias, and notification_message.

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: uploading one App Store screenshot for a single iPhone display size from a master image. It is clear what the tool does, but it does not explicitly distinguish itself from the sibling upload_screenshot tool, so it falls short of a 5.

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?

It explains practical usage constraints: pass base64 or URL, pick exactly one display type per call, and call again for additional sizes. However, it does not say when to use this tool versus upload_screenshot or other siblings, so guidance is implied rather than complete.

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