spotify_set_volume

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

With no annotations, the description carries the full behavioral burden, and it adds nothing beyond stating the range. It doesn't disclose that this mutates live playback, what happens with no active device, whether an invalid device_id errors, or permission/auth requirements. 'Set' implies mutation but no consequences are described.

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 tight phrase that is front-loaded with the action. The parenthetical range is redundant with the schema, so it is not perfectly waste-free, but it is not bloated.

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 simple setter with no output schema and complete schema coverage, the description is minimally adequate. It still omits the meaningful unknowns: device defaulting behavior, failure modes when nothing is playing, and whether this affects only the active session.

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% and the schema already documents both volume_percent (with min/max 0-100) and device_id. The description's '(0-100)' merely repeats the schema constraint, adding no syntax, default, or targeting semantics for device_id.

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 (set + playback volume) with the valid range, so an agent can distinguish it from siblings like spotify_play or spotify_transfer_playback. It stops short of naming any sibling or clarifying how it interacts with the currently active device.

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 about when to use this versus alternatives or what preconditions apply (an active playback session, whether device_id must be supplied or defaults to the active device). Usage is only implied by the tool name.

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