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

No annotations are contradicted. The description adds context by specifying allowed image formats and the owner's store, but it does not disclose behavior like file size limits (already in schema), return values, or overwrite semantics. The annotations already indicate a mutating operation, so the description's added value is modest.

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 a single sentence, front-loading the action and target. It contains no filler and every word adds value.

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 simple one-parameter upload with no output schema, the description covers purpose, permitted formats, and destination. It could mention the return value or authorization requirement, but the annotation and schema provide some context. Overall, it is reasonably complete.

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 0%, so the description must compensate. It does by naming accepted image formats (PNG, JPEG, GIF, WebP), which adds meaning to the single contentBase64 parameter. However, it does not explicitly explain that the parameter must be Base64-encoded, though the name implies it.

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 clearly states 'Upload one PNG, JPEG, GIF, or WebP image to the authenticated owner's template media store.' It specifies the verb (Upload), the resource (image), and the target (template media store), distinguishing it from sibling tools like storage.create_bag or sites.publish_files.

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 explicit when-to-use guidance or mention of alternatives. The description implies a use case (uploading images for templates) but does not state when to prefer this over similar tools like sites.publish_files. Clear context is present, but exclusions are missing.

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