Saves movie frames as a sequence of PNG images using a filename prefix; PyMOL appends zero-padded frame numbers for easy animation export.
Saves a series of PNG images for movie frames
| Name | Required | Description | Default |
|---|---|---|---|
| prefix | Yes | Filename prefix; PyMOL appends a zero-padded frame number. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.5.1Input schema / properties / prefix / descriptionAdded value: +"Filename prefix; PyMOL appends a zero-padded frame number."v1.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true and idempotentHint=true, so the safety profile is partly covered, but the description never clarifies what is actually destroyed or written: no mention of files landing in the working directory, one file per frame, or that existing files are overwritten. Given destructiveHint=true on an image-saving tool, that clarification is exactly what the description should supply.
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?
A single front-loaded sentence with no filler. It is efficiently sized, though the brevity borders on under-specification rather than tightness.
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 and the tool takes one required parameter, so the burden is light. Still missing are the output location, the fact that a movie/frame range must be defined, and overwrite behavior — details an agent needs before invoking a destructive file-writing command.
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 100% and the schema already explains that PyMOL appends a zero-padded frame number to the prefix. The description adds no meaning beyond that, so the baseline 3 applies.
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?
Specific verb ('Saves') plus resource ('series of PNG images for movie frames'), which implicitly distinguishes it from the single-image 'png' sibling. It stops short of naming that sibling explicitly, so an agent must infer the distinction.
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?
'for movie frames' implies the precondition that a movie must be defined, but nothing states when to prefer this over 'png', nor what happens if no movie is loaded. Usage is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.