adjustVolume

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

With no annotations to lean on, the description carries the full burden, and it does disclose one genuinely useful non-obvious fact: Spotify Premium is required. It says nothing about what happens at the -100/100 bounds, whether the adjustment is clamped, what occurs if the account lacks Premium, or whether deviceId defaults to the active device.

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 short sentences, front-loaded with the purpose and no filler. Sentence two largely duplicates the schema's own sign-convention text, which is a minor redundancy, but the description stays tight overall.

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 two-parameter mutation with no annotations and no output schema, the Premium prerequisite is a valuable addition, but the description leaves out deviceId defaulting, bound behavior, and error handling. It is adequate but not complete for a state-changing playback tool.

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 both parameters (including the -100 to 100 range and sign convention) are already fully documented in the schema, and the description mostly restates them. The one gap remaining in both places is deviceId defaulting behavior, which neither the schema nor the description clarifies.

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 (adjust) and resource (playback volume) plus the key qualifier that the change is relative, which is the main way it differs from a volume-setting tool. It stops short of naming the sibling setVolume, so the agent must infer the distinction from the word 'relative' alone.

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?

Sign convention is given (positive increases, negative decreases), which implies when to use this relative tool versus an absolute setter, but the description never names setVolume or states an explicit condition for choosing between them. Usage is implied rather than spelled out.

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