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

Annotations cover the safety profile (not read-only, not destructive, closed world), and the description adds real value beyond them: team-wide sharing semantics, the id (hashid) return, the plan-limit failure mode, and that repurpose_textual_content costs 1 credit per minute charged once per video. Remaining gap is what happens to skipped/omitted fields on defaults, though composition_parameters defers to describe_agent_settings.

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?

Two tight paragraphs, front-loaded with the definition and the required parameter before optional detail, and the return/failure note closes it. Minor redundancy in re-listing the personality_preset values that the schema already enumerates.

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?

With no output schema, the description correctly states the return (new agent id/hashid) and the failure mode, and it delegates the nested rendering/caption objects to describe_agent_settings. For a 7-param tool with nested objects this is nearly complete, though the deferral leaves composition_parameters fully opaque in this definition.

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 100%, so the baseline is 3; the description still adds cross-tool routing (caption_preset comes from list_caption_presets, composition_parameters/caption_style_overrides from describe_agent_settings), the conditional requirement on custom_personality_description, and the credit cost of the repurpose flag. It does partly restate the personality_preset enum already in 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+resource ('Create a processing agent') and immediately defines what an agent is — a saved team-shared configuration controlling video processing/rendering. This clearly separates it from list_agents, update_agent, and submit_video without opening any schema.

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 the required/optional parameter split, the conditional rule for custom_personality_description, and a failure condition (plan's agent limit). It implies creation-versus-modification via the sibling set but never explicitly says 'to change an existing agent use update_agent'.

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