arrangement_edit_clip

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

Annotations already declare non-readonly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely new behavior: partial-update semantics (unspecified fields preserved), type-dependent length constraints (MIDI grows or shrinks, audio only shrinks), and reversibility ("Undoable"). It does not cover failure modes or the response shape, keeping it at 4.

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?

Three tight sentences: the core operation and its editable fields come first, the patch rule second, an example third, with "Undoable" as a one-word tail. Every sentence carries distinct information with no redundancy against the schema or annotations.

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 7-parameter mutation tool with no output schema, the description covers the essentials an agent needs: what changes, what is preserved, undo availability, and the audio/MIDI length asymmetry. Minor gaps remain around error conditions (nonexistent clip index, out-of-range gain) and confirmation behavior, but nothing critical for correct invocation is 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 coverage is 100%, so the baseline is 3, but the description earns above baseline by explaining semantics the schema cannot: omitted fields retain their value, and length_beats behaves differently by clip type (MIDI can extend, audio cannot). It also cross-references where the clip and track indices come from (arrangement.get, tracks.list).

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?

States a specific verb and resource ("Change one timeline clip") and enumerates exactly which attributes can be modified: position, length, mute, name, gain. It also pins the identifier source ("index from arrangement.get"). It does not explicitly differentiate itself from near siblings such as arrangement_place_clip, arrangement_copy_clip, arrangement_remove_clip, or clips_set_length, so an agent must infer that this is the in-place mutation tool.

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?

Provides a concrete usage scenario ("mute the bass in the second half of a drop after copying it there") that clarifies the intended editing workflow, plus the patch rule "Fields left out stay," which tells the agent it can make partial updates safely. No explicit when-not-use or named alternative, so it stops short of a 5.

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