play_music

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions a potential failure on older Android versions, which is useful context, but doesn't cover other important aspects like whether this requires specific permissions, how it handles network errors, or if it plays audio in the background. The description adds some value but leaves significant gaps.

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?

The description is efficiently structured with a clear purpose statement upfront, followed by a warning, and then parameter/return documentation. Every sentence serves a distinct purpose without redundancy. The formatting with sections for 'Args' and 'Returns' enhances readability.

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?

Given the tool's moderate complexity (audio playback with potential platform issues), no annotations, and an output schema that only specifies a string return type, the description is somewhat complete but could be improved. It covers the basic operation and a key warning, but lacks details about audio formats supported, playback controls, or error handling specifics that would be helpful for an agent.

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?

The description explicitly documents the single parameter ('url') with its type and purpose, adding meaningful context beyond what the input schema provides (which has 0% description coverage). Since there's only one parameter and it's fully explained in the description, this compensates well for the schema's lack of documentation.

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 clearly states the tool's purpose with a specific verb ('Play') and resource ('music from a URL'), making it immediately understandable. However, it doesn't differentiate from sibling tools like 'stop_music' beyond the basic action, which prevents a perfect score.

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 provides no guidance on when to use this tool versus alternatives. While it includes a warning about Android 10 compatibility, this is a technical constraint rather than usage context. There's no mention of prerequisites, alternatives, or scenarios where this tool is preferred over others.

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