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

The readOnlyHint and openWorldHint annotations already establish that this is a safe, account-scoped read. The description adds genuinely useful behavior beyond that: the exact font-family/weight/style contract and the fallback to Inter when a name doesn't match exactly. It does not mention ordering, pagination, or behavior with an empty library, so the addition 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?

Content is front-loaded — what the tool returns comes first, then how to use each item. Every sentence carries information (asset types, template usage, CSS contract, fallback rule, Google Fonts exclusion), though the font-fallback aside is slightly parenthetical and the opening is a noun phrase rather than a crisp statement of action.

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 output schema, the description carries the burden of describing returns, and it does: URLs per image, family/weight/style per font, plus storage used. It leaves minor gaps such as response ordering or empty-state behavior, but an agent can call this correctly and interpret the result from what is stated.

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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The description instead spends its words on the return shape, which is the right allocation.

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 names both resources it returns (uploaded images: logos, badges, overlays; and custom fonts) plus the storage-used metric, so the agent knows exactly what this tool surfaces. It doesn't use an explicit verb like 'list', relying on the title, but the resource scope is unambiguous and distinguishes it from the upload_image/upload_font siblings.

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 gives clear workflow context — image URLs go into code templates as <img src>, font names go into CSS — and an explicit exclusion: Google Fonts need no upload, so don't look for them here. It stops short of naming sibling alternatives (e.g., get_brand_context_starter) or stating prerequisites, so it's short of a full when/when-not/alternatives treatment.

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