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

Annotations declare the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower, yet the description still adds real context: the audio is persisted into Mureka storage, the response shape is named, and an approximate latency/duration (~5-15 s) is disclosed. It does not mention auth requirements or whether imported files persist/expire, keeping it short of a 5.

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?

Four tight sentences, front-loaded with the core action, then the return payload, then the next-step routing. The trailing 'GET /files/youtube' is a compact implementation hint rather than filler.

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?

There is no output schema, yet the description names the returned fields and their use, and it links to the three tools that consume the result plus the sheet-music alternative. Nothing an agent needs to call this correctly is missing.

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 100% and both parameters (url, account) are already documented in the schema. The description repeats the 'YouTube link' notion but adds no format details, accepted URL variants, or the account-selection behavior beyond what the schema states, so baseline 3 applies.

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+resource ('Fetch the audio of a YouTube link into Mureka storage') and enumerates the return payload (title, duration, mp3 url). It is clearly distinguishable from siblings like mureka_get_sheet_music and mureka_upload_* which it explicitly names.

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?

Explicitly routes the agent downstream: 'Pass that mp3 url as url to mureka_upload_reference, mureka_upload_vocal or mureka_upload_motif.' It also names the alternative path for sheet music ('mureka_get_sheet_music takes the YouTube link directly'), so when-to-use and when-not-to-use are both covered.

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