Play Music/Video

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

While annotations indicate readOnlyHint false (mutation) and destructiveHint false, the description does not disclose behavioral traits like what happens if a file is already playing (e.g., stops, queues, or replaces). With limited annotation burden, the description should add this context but does not.

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 two sentences, front-loading the core purpose in the first sentence and providing an illustrative example in the second. No redundant information.

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?

With one parameter and no output schema, the description covers the basic use case. However, it lacks details about start behavior relative to current playback (e.g., does it pause current? Add to queue?). Given tool complexity and siblings, slightly more context would be beneficial.

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 has 100% coverage with parameter description 'File path or search term to find and play'. The description adds value by explaining that searching occurs in Music and Videos folders when a name is given, which is not in the schema. This additional context raises it above baseline 3.

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 'Play a file by path or search term', using a specific verb and resource. It distinguishes from sibling tools like mpv_add, mpv_browse, etc., which have different purposes. The mention of searching Music and Videos folders adds clarity.

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 (to play a file), but does not explicitly state when not to use or provide alternatives among siblings. No exclusions or comparisons are given, leaving the agent to infer usage context.

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