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

Annotations already disclose that this is a non-readonly, idempotent, non-destructive operation. The description adds useful behavioral context beyond that: it returns the next draft with the same shot list, set in the chosen photo, and involves no director call and no cost.

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 definition is compact and front-loads the core action, then adds return behavior and selection constraints. There is minor awkwardness in the run-on first sentence, but no substantial wasted text.

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 mutating tool with no output schema, the description explains the returned artifact: the next draft with the same shot list set in the new photo. Annotations cover safety and idempotency, and the parameter constraints are sufficiently described, though error or plan-state conditions are not covered.

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?

All three parameters have complete schema descriptions, so the baseline is 3. The description adds meaningful constraints for stock_id, namely same kind of place and no people, and ties the place parameter to one of a plan's places.

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 title and description clearly state a specific action: changing a place's photo within a plan by supplying a stock photo. It also distinguishes the tool from search by requiring a stock_id from search_stock and from render by noting no director call and no cost.

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 a clear prerequisite workflow: pick a photo from search_stock, of the same kind of place, with no people. It does not explicitly name when not to use this tool or list alternative sibling tools, so it falls short of full when/when-not guidance.

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