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

With no annotations, the description carries the full burden and does add useful behavioral context: it discloses a $0.005 cost and specifies scroll-capture behavior. However, it omits side effects, how the artifact is returned/stored, rate limits, and failure characteristics, leaving important behavior underspecified.

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 a single sentence that front-loads the critical paid constraint, then states the action and output format with no filler. Every word adds value and the structure is appropriately compact.

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 tool has no annotations and no output schema, so the description must explain what the caller can expect, but it only says 'video artifact' without clarifying whether the result is a URL, file path, binary, or stored object. The large sibling set and absence of usage routing further reduce the agent's ability to understand the full context.

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 schema already documents all three parameters including the format enum, durationMs default, and max value. The description adds no parameter-level meaning beyond what the schema provides, so the baseline 3 is appropriate.

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 clearly identifies the action ('scroll-capture a page') and the output ('MP4/WebM video artifact'), giving a specific verb, resource, and result format. It does not explicitly name sibling tools, but the video-specific wording distinguishes it from the likely capture, preview, and thumbnail tools in the sibling list.

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 versus the many webcap_* siblings, nor any mention of prerequisites, limitations, or exclusions. The only operational hint is 'PAID', but no selection criteria or alternative routing is provided.

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