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

Annotations declare it is not read-only and not idempotent; the description confirms and enriches this with concrete costs (100 vs 20 Gold), the entitlement requirement (Premier plan), re-charge on repeat calls, and the returned artifacts (wav/mp3 per stem, BPM, stems_id or jobid). That is precisely the added context beyond annotations.

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 core operation is front-loaded ('Split a song into stems') and every clause carries needed information (plan, pricing, reuse, output). It is very dense and relies on stacked parentheticals, which slightly hurts readability but not substance.

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 mutation-style extraction with no output schema, it covers the entitlement gate, cost tradeoff, reuse path, expected job duration/outputs, and follow-up tool for the async jobid. Nothing an agent needs to call it 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 coverage is 100% and both parameters are documented there, including the default and prices for all_stems, so the description largely restates schema content. It adds a little cost framing but no new syntax or format detail beyond the schema baseline.

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 ('split a song into stems') with the scope of each mode. It names the sibling tools it is not (mureka_download_stems for reuse, mureka_download_song for the basic package), so an agent can distinguish it from related stem/download tools.

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 states when to use it, the plan prerequisite (Mureka Premier), and names alternatives with the conditions that select them (reuse stems_id vs. basic package via mureka_download_song). The 'every call is a new extraction and is charged again' warning tells the agent when NOT to call it.

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