Video Download

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds a genuinely useful behavioral fact not present in the annotations: a cost of 1 credit per call. It says nothing, however, about whether the call is synchronous, whether it produces a job to poll with wait_for_job, or how webhook delivery interacts with the response, which matters for an 8-parameter external-fetch 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 text is short and front-loaded, but the first sentence is a pure restatement of the title and therefore wasteful, leaving only the credit-cost sentence with actual content. Brevity here reflects under-specification rather than disciplined editing.

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 tool with 8 parameters, webhook callbacks with retry semantics, truncation via max_duration, and an external open-world fetch, the description omits return behavior, job/polling semantics, and any usage conditions. With no output schema, the description should carry more of that burden than it does.

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 every parameter is documented in the schema, including the fields, webhook_url, max_duration, and format/quality options. The description adds no parameter meaning of its own; baseline 3 applies because the schema carries the full load.

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?

"Video Download" merely restates the tool name and title with no verb-plus-resource specificity and no differentiation from the sibling audio_download or media_metadata. The only added information is the credit cost, which is pricing, not 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?

There is no guidance on when to use this tool, when to prefer audio_download, or how it relates to jobs/wait_for_job for retrieving results. The agent must infer everything from the name alone.

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