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Glama

Cut a clip

extract_clip
Idempotent

Cut a precise segment from a remote archive.org video into a verified H.264 MP4 with provenance JSON and three check frames. Repeating the same cut returns the existing clip.

Instructions

Cut start_s..start_s+duration_s from a remote archive.org video into a verified H.264 MP4 under BROLL_HOME/clips, with a provenance JSON beside it. Returns 3 check frames. Repeating the same cut returns the existing clip.

Input Schema

NameRequiredDescriptionDefault
fileYes
audioNoB-roll is usually silent; false strips audio.
briefNoThe brief this clip answers; stored in the provenance record.
labelNoShort name used in the output file name.
start_sYes
duration_sYes
identifierYes

Output Schema

NameRequiredDescriptionDefault
pathYes
cacheYes
clip_idYes
verifiedYes
provenanceYes
provenance_pathYes
upstream_requestsYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A4/5.0
Behavior4/5

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

Beyond the annotations (write, idempotent, open-world), the description discloses the output container and codec, the destination directory, and the sidecar provenance file, plus that 3 check frames are returned. It does not mention failure modes (e.g., download errors, invalid time ranges) or that audio is stripped/handled, but the added context is substantial.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense sentences with zero filler, front-loading the core action and slice definition, then the output artifact and idempotency behavior.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description needn't detail the returned frames, and it already covers output format, location, and idempotent repeat behavior. Missing pieces are prerequisites and the semantics of the optional audio/brief/label parameters.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 43%, yet the description only clarifies start_s and duration_s semantics (the slice definition) and hints at identifier/file via 'remote archive.org video'. Optional parameters audio, brief, and label are not explained in the description, so it only partly compensates for the coverage gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (cut), the resource (a remote archive.org video), the exact time slice derived from start_s and duration_s, and the output artifact (verified H.264 MP4 under BROLL_HOME/clips plus a provenance JSON). This is clearly distinguishable from search_footage, inspect_item, and get_provenance.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Conveys implied usage (produce a clip after locating footage) and explicitly notes that repeating the same cut returns the existing clip. However, it never states when to prefer this over siblings like inspect_item or search_footage, nor any preconditions such as inspecting the item first.

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