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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the safety profile is clear. The description adds value by disclosing the return format (compel ID, status, tracking links), which is not in the annotations. However, the false claim about reference media slightly reduces trustworthiness.

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 concise, consisting of one sentence that covers the action, inputs, and outputs. However, the 'optional reference media' phrase is unnecessary and potentially misleading, so not every element earns its place.

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?

The description captures the core creation purpose and return information, which is important given the lack of an output schema. However, it omits the fact that style must be selected from list_styles and falsely claims reference media support, leaving the tool's full behavior only partially described.

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?

All schema parameters have descriptions, so baseline is 3. However, the description introduces 'optional reference media' with no corresponding parameter, actively confusing parameter understanding. It adds no useful semantics for the actual parameters beyond what the schema already provides.

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 it creates a Compeller generation job from primary audio media, with a specific verb and resource. It distinguishes from sibling create_compel_from_music, but the mention of 'optional reference media' is not supported by the schema, slightly muddying the purpose.

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?

It provides clear context that this is for creating a compel from uploaded audio, but does not mention alternatives or exclusion criteria. The unsupported 'optional reference media' reference could mislead an agent into thinking there is a parameter for it, harming usage guidance.

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