volume_down

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

The annotations already indicate readOnlyHint=false, so the mutating nature is known. The description adds that the mutation targets the master volume, but it does not disclose edge behavior such as clamping at minimum volume, whether negative step values are allowed, or any system-level side effects.

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 clear sentence with no filler or repetition. The action is front-loaded and the sentence earns its place.

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 one-parameter tool, the description is close to sufficient, but the ambiguous meaning of 'step' and the lack of any guidance about bounds or return behavior leave meaningful gaps. An agent could call it correctly in the common case, but not with full confidence about edge cases.

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 description coverage is 0%, so the description carries the full burden for explaining the step parameter. The phrase 'by a step' only loosely ties the integer parameter to the decrement amount; it does not clarify units, allowed range, whether negative values would increase volume, or how 'a step' maps to actual volume change.

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?

The description states a specific action ('Decrease') and resource ('master volume'), which clearly distinguishes it from siblings like volume_up and set_volume. However, it says 'by a step' rather than 'by the specified step,' leaving slight ambiguity about whether the required step parameter is the decrement amount.

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 implies when to use the tool: when the caller wants to lower the master volume incrementally. It does not explicitly contrast with volume_up, set_volume, or mute_audio, so an agent receives no direct guidance on choosing among these siblings.

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