Apply caption template

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false; the description adds the genuinely useful behavioral fact that execution is synchronous rather than queued through autonomous_edit. It does not disclose whether existing captions are overwritten (especially in 'clear'/'recreate' modes) or what the synchronous call returns, which matters for a mutation 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?

A single sentence with zero filler, and the synchronous/alternative-path distinction is front-loaded where an agent will see it first.

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 mutation tool with a nested 'scene' object, a six-value mode enum, and no output schema, the definition is adequate but thin: mode semantics and the return behavior of the synchronous call are unexplained. Annotations and the 75% schema coverage fill enough of the gap that this is not a serious deficiency, but the description could say more.

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?

With 75% schema description coverage and four parameters, the schema carries most of the documentation burden. The description adds nothing about the enum values for 'mode' (the one parameter lacking a schema description) or about scene vs project_id precedence, so 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?

States a specific verb and resource ('Apply a caption template to a scene') and explicitly contrasts with the sibling autonomous_edit path, so an agent can distinguish it from the autonomous workflow. It does not convey what applying a template actually does to existing captions, but the action itself is unambiguous.

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 phrase 'synchronously (without going through autonomous_edit)' implies when to pick this over the autonomous siblings, which is useful routing context. However, it gives no guidance on the six modes (add vs recreate vs clear etc.), nor on when to use scene vs project_id, leaving key selection decisions to inference.

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