suno_extend

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that the operation costs credits, returns a task_id, and imposes constraints (model must match source version, all custom fields required in custom mode). It also reveals the inheritance behavior when custom fields are omitted. This covers the most consequential behaviors, though it does not describe failure modes or whether the original take is modified.

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 dense sentences with no filler. It front-loads the purpose and then packs mode rules, requirements, and cost into the second sentence. While not formatted as bullet points, it is efficient and every clause adds value.

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 tool with 16 parameters and two modes, the description covers the essential usage context: purpose, mode selection, required parameters per mode, cost, and return value. It does not explain every parameter's meaning, but that is partially the schema's role (though schema is weak). The description provides enough for an agent to call the tool correctly in most scenarios.

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 only 19%, so the description must compensate for undocumented parameters. It explains the critical mode logic (inherit vs. custom) and the relationship between prompt/style/title/continueAt, and clarifies that audioId and model are the minimum for inherit mode. However, many parameters (personaId, vocalGender, negativeTags, etc.) remain unexplained in both the description and schema, leaving gaps for an agent.

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 'Extend an existing Suno task's take (generate/extend)', which identifies the verb, resource, and operation. It distinguishes from siblings like suno_generate (new generation) and suno_cover (cover) by specifying it operates on an existing task's take, and the phrase 'generate/extend' clarifies the action.

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 gives explicit instructions on when to use the tool and how to configure it: omitting custom fields inherits source parameters, while custom mode requires all of prompt+style+title+continueAt. It also notes the model must match the source model version in custom mode. While it doesn't explicitly name alternative tools for non-extend use cases, the context is clear enough for an agent to decide when to use this vs. other Suno tools.

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