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

Annotations already signal a mutating operation via destructiveHint=true, and the description reinforces this with 'WRITE.' It adds meaningful behavioral context: when `source` is provided, api.video ingests from that URL, and raw file bytes cannot stream through MCP. This goes beyond the annotation without contradicting it.

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 sentences with no wasted words. The core purpose is front-loaded in 'WRITE. Create a new video object,' followed by the essential source guidance and the endpoint. Every sentence 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 is adequate for a creation tool but leaves gaps: it does not explain what happens when `source` is omitted, and with no output schema it does not indicate what response the agent should expect. Given 9 parameters and complexity around ingestion, slightly more detail on behavior and return value would improve completeness.

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%, so the baseline is 3. The description adds extra semantics for `source`, explaining it as a public URL, recommending it for hosted use, and clarifying why raw bytes cannot be used. Other parameters are left to the schema, which fully documents them.

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 states a specific verb and resource: 'Create a new video object.' It clearly differentiates from siblings like apivideo_create_live_stream and apivideo_update_video by naming the object type and including the endpoint 'POST /videos.'

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 useful context for the `source` parameter, recommending it for hosted use, but it does not explicitly say when to choose this tool over alternatives or when not to use it. Usage is implied by 'Create a new video object,' but no exclusions or sibling routing are provided.

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