save_png

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

With no annotations provided, the description carries the behavioral burden and does disclose the invocation context, the clipboard/sandbox condition, accepted input format, and that it returns the written path. It does not mention overwrite behavior, permissions, or error handling for file writes, which are relevant gaps for a save operation.

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 warning not to call the tool is front-loaded, and the remaining sentences are short and purposeful. Every sentence adds either usage context or a relevant input/output detail without repetition.

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?

An output schema exists, so the description need not explain return values in detail, and it already states that a path is returned. For a two-parameter internal helper it is largely complete, though filename semantics remain underspecified.

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 partially does by explaining that png_base64 is a base64 PNG with an optional data:image/png;base64, prefix, but it says nothing about the filename parameter's expected path, directory, extension, or overwrite semantics.

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 action (save a PNG), the expected input (base64 PNG), and the result (returns the written path). It also explicitly distinguishes this from the generate_* tools, which already write their own PNG and SVG files, so an agent can tell this is not the normal image-generation path.

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 an unusually explicit usage rule: never call this directly, because the panel's export button invokes it when sandbox clipboard access is blocked. It also names the relevant alternative behavior by noting that generate_* tools already write their files themselves.

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