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

No annotations are provided, so the description carries the full burden. It usefully discloses the credit cost and a mandatory user-confirmation step, but says nothing about permission needs, whether stitching is synchronous or async (dangling get_render_status suggests async), whether an existing projectName is overwritten, or what the call returns.

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?

Three front-loaded sentences with no filler; the purpose and the confirmation gate are up front. Slightly verbose in restating the overlay question rather than referencing textOnDemo directly.

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 an 11-parameter render-style tool with no output schema, the description covers the input-side essentials but omits the execution model (sync vs async render, result retrieval, failure behavior). With no output schema present, the description should indicate what a successful call yields.

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% across all 11 parameters, so the schema already documents each field. The description only reinforces the hook-vs-demo text distinction that textOnDemo already covers, adding no syntax or format detail 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?

States a specific verb (Assemble/stitch) and resource (hook + demo clips into a final vertical video), and names the output artifact. An agent can distinguish it from generate_video or remix_hook which produce different artifacts.

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?

Gives a concrete pre-invocation requirement ('ask the user whether the text overlay should appear on the demo section') and surfaces the cost (2 credits). It does not, however, compare against alternatives like remix_hook or generate_video for when stitching is the right choice.

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