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

Annotations already establish readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered. The description adds the content scope (tracks usable for a new listing video) and the key returned fields (musicId, tempo, energy), but says nothing about list size, ordering, or whether the result is exhaustive, so it adds only modest behavioral context.

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 short sentence with no redundant wording, and the scoping qualifier ('a new listing video can use') is front-loaded. Nothing could be removed without losing 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 zero parameters, rich annotations, and an output schema, the description needs only to establish purpose and content scope, which it does. The one gap is sibling differentiation in a crowded music-tool namespace, where an agent could otherwise confuse this with list_music or list_generated_music.

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 tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. The description's mention of musicId, tempo and energy is return-value context rather than parameter guidance.

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 names the resource (songs) and scopes it to those 'a new listing video can use', which tells an agent this is the catalog of usable tracks rather than generated or library music. It stops short of a specific verb and does not explicitly distinguish itself from close siblings like list_music or list_generated_music, so an agent must infer the difference.

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 phrase 'a new listing video can use' implicitly signals when to call it — during listing video creation when choosing music — but there is no explicit when-to-use, when-not, or named alternative among the many music-related siblings (list_music, list_generated_music, propose_music, request_music_generation). The guidance is inferable but not stated.

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