music_control

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

Annotations already declare it a non-destructive, idempotent, open-world write, so the safety profile is covered. The description adds useful context beyond annotations by disclosing the required permission (automation:Music) and version, but stays silent on the human-approval flow implied by _approvalId, which is meaningful for a write tool.

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 the action set stated up front, plus a compact bracketed metadata tag. No wasted prose, though the action enumeration is redundant with the schema enum.

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 return values need not be explained, and annotations cover the safety profile. However, for a write tool that requires an idempotency key and supports a human-approval ID, the description omits any mention of the approval/retry behavior an agent needs to invoke it correctly.

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 67%, and the description's enumeration of the action values merely restates the enum already defined in the schema. It adds no syntax or meaning for _approvalId or _idempotencyKey, so it does not compensate for the uncovered portions of the schema.

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 (Control) and resource (Music playback), and enumerates the four transport actions, so an agent can tell this is playback transport control rather than library browsing. It does not, however, distinguish itself from the sibling music_play_track, leaving ambiguity about which to prefer.

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?

The description lists the fixed actions but gives no when-to-use guidance, no prerequisites, and no alternative tools. With music_status, music_search, and music_play_track as siblings, an agent must infer on its own when this tool is the right choice.

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