SunoMCP

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

With no annotations provided, the description carries the full burden. It discloses the async nature of the operation by mentioning 'Task ID' in the return value, which is critical behavioral context. However, it lacks details on whether the extension creates a new file or modifies the existing one, processing time, or error handling behaviors.

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 optimally structured with the core purpose first, followed by sibling comparison, then bulleted usage conditions, and finally return type. Every sentence serves a distinct purpose; no redundancy or filler text.

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 presence of an output schema, the description appropriately summarizes the return value ('Task ID and the extended audio information') without over-specifying. It establishes the necessary workflow context (upload → extend) and distinguishes from similar tools, though it could explicitly note the async/long-running nature of the operation.

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%, establishing a baseline of 3. The description mentions that audio must come from suno_upload_audio, but this constraint is already explicitly stated in the audio_id schema description ('Must be an audio uploaded via suno_upload_audio'), so the description adds no new semantic information beyond the schema.

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 opens with a specific verb+resource ('Extend an uploaded audio... with new AI-generated content') and immediately distinguishes from the sibling tool suno_extend_music by clarifying this works with 'audio you uploaded via suno_upload_audio.' This sibling differentiation is explicit and precise.

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?

Provides explicit 'Use this when:' bullet points stating clear conditions (uploaded your own music, want AI-generated sections). It explicitly names the alternative (suno_extend_music) and contrasts it, giving the agent clear guidance on tool selection.

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