wp_upload_media

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

With no annotations provided, the description must carry the behavioral disclosure burden. It clearly states the mutating upload action, requires base64 data, and adds a 10MB size limit. However, it does not mention response/return behavior, permissions, or failure handling, leaving meaningful operational gaps.

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 two sentences with no filler. The core action is front-loaded, and the maximum size constraint is a valuable addition without unnecessary detail.

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 upload tool, the description is nearly complete: required inputs, encoding, and size limits are covered, and the schema documents the optional fields and title default. The only notable gap is that no output/return behavior is described, but this is minor for an upload operation where the side effect is the main purpose.

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?

All four parameters are fully described in the schema with 100% coverage, so the baseline is 3. The description adds the 10MB file size cap and reinforces base64 encoding, which is useful but only marginal beyond the schema's own parameter descriptions.

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 a specific action (upload), a clear resource (WordPress media library), and the input format (base64), making it instantly distinguishable from sibling media tools like wp_list_media, wp_get_media, and wp_delete_media.

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?

No guidance is provided about when to use this tool versus alternatives, and no exclusions or fallback tools are mentioned. The uniqueness of the upload action is implied by the name, but the description itself offers no selection help.

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