plunk_upload_image

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

With no annotations provided, the description carries the burden and does well: it discloses the JSON shim behavior and the mismatch with the underlying multipart endpoint. It doesn't mention return values or error handling, but the key caveat is transparently surfaced.

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?

Two sentences: the first states purpose and usage, the second adds a necessary caveat. Nothing is wasted, and the most important information 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 tool with no output schema and no annotations, the description covers the essential semantics: what the tool does, how to pass the image, and a potential compatibility issue. It doesn't explain post-upload behavior or response format, but the core context is well covered.

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 schema already covers content and contentType, but the description adds the crucial detail that 'content' must be base64-encoded. The filename parameter is left without description, but the added base64 context improves understanding beyond the raw schema.

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 the tool uploads an image and gives a concrete use case ('for use in templates or campaigns'). It uses a specific verb ('Upload') and resource, distinguishing it from sibling tools like contact management or sending.

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 provides explicit how-to guidance ('Pass the file as base64') and an alternative ('if your Plunk version requires multipart, use the dashboard upload flow'). This clarifies when to use this tool versus the alternative, and even highlights a compatibility caveat.

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