Add a timestamped marker to a sidecar JSON for media or timeline files, enabling named annotations and color-coded notes for video editing workflows.
Add a marker to a sidecar JSON next to a media or timeline file (FFmpeg has no built-in markers).
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| note | No | ||
| time | Yes | ||
| color | No | yellow | |
| target | Yes | ||
| allow_any_path | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It reveals the sidecar JSON mechanism but does not disclose file naming, duplicate behavior, overwrite semantics, path restrictions, permissions, or reversibility of the add 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 description is a single efficient sentence with zero wasted words. It front-loads the core action and adds a useful contextual reason for the sidecar approach.
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 six parameters, zero schema descriptions, and no annotations, the description is far too sparse. It omits parameter formats, sidecar naming conventions, path handling, and any behavioral constraints, leaving critical information missing.
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% and the description adds no meaning to any of the six parameters. It does not clarify target, time units, name constraints, note/color defaults, or allow_any_path behavior, leaving the agent without the information needed to supply correct values.
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?
Description states a specific verb and resource: add a marker to a sidecar JSON next to a media or timeline file. The FFmpeg context and sidecar mechanism make it distinguishably different from siblings like list_markers.
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 on when to use this tool versus alternatives such as list_markers or other edit tools. The parenthetical about FFmpeg explains why sidecars exist but does not state conditions, prerequisites, or when not to use this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.