generate_video

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

With no annotations, the description must disclose behavioral traits itself. It mentions the required environment variable, the return shape ({ cmid, video_url, page_url }), and the asynchronous-ish wait time (~1 minute). It also implies a write operation by 'embed it in a new mod_page'. It could add side effects like cost or idempotency (which schema hints at), but the provided context is above average for a mutation tool.

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 sentences, front-loaded with the primary action, and every clause adds value: the resource (mod_page), the model (Veo 3.1), the language requirement, the dependency (API key), the return value, and the time estimate. No filler or repetition of schema content.

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 complex 11-parameter tool with no output schema, the description provides essential operational context: return format (not in schema), time-to-completion, and prerequisite. It could mention deletion or failure modes, but given the high schema coverage and the concise description, it is sufficiently complete for an agent to select and invoke the tool correctly.

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 91%, so the description doesn't need to explain parameters. The description adds no extra parameter details beyond what the schema already provides (e.g., prompt must be Italian, idnumber for idempotency). Baseline 3 is appropriate because the schema handles parameter semantics, and the description doesn't need to compensate.

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 ('Generate a short Italian-language video with Google Veo 3.1 and embed it in a new mod_page in Moodle'), clearly distinguishing it from the sibling tools, which are course management, quiz, and messaging tools. It unambiguously states what the tool does and its primary side effect (creating a mod_page).

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 provides clear context for when to use the tool: for Italian-language short videos, with a stated prerequisite (GEMINI_API_KEY) and performance expectation (~1 minute). It does not explicitly name alternative tools or exclusion scenarios, but no sibling tool serves the same purpose, so the context is sufficient. A slight deduction for lacking explicit 'when not to use' guidance.

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