LumaMCP

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

With no annotations provided, the description carries the full burden but omits key behavioral details: it does not clarify whether this creates a new video resource or modifies the existing one, nor does it mention the asynchronous nature implied by the 'Task ID' return value or how to retrieve the final result.

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?

Excellent structure with one-line summary, sibling comparison, bulleted usage conditions, and explicit Returns section. Every sentence serves a distinct purpose with no redundant 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 100% schema coverage and the existence of an output schema (mentioned in description), the definition is nearly complete. Minor gap: it could explicitly note that this initiates an async task requiring subsequent status checks (implied by 'Task ID' but not stated).

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 adds context that the URL comes from 'previous generation' reinforcing the schema, but does not add syntax details, validation rules, or semantic meaning beyond what the schema properties already provide.

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 pair ('Extend an existing video') and immediately distinguishes from the sibling tool luma_extend_video by clarifying it uses 'video URL instead of video ID', making the scope and differentiation crystal clear.

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 detailing the exact scenarios (having URL from previous generation, lacking video_id) and implicitly identifies luma_extend_video as the alternative, giving clear selection criteria.

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