duplicate_frame

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

Annotations declare readOnlyHint=false and destructiveHint=false, so the mutation/safety profile is already covered; the description goes beyond that by disclosing error semantics (rejection with the sprite's valid range instead of silent clamping) and 1-based indexing. It stops short of saying what is returned or whether the change is persisted to `filename`.

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 short sentences, front-loading the verb+resource and the insertion position, with the precondition detail following. No filler; each clause adds usable information.

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 should clarify the return value (new frame index?) and whether `filename` identifies the file being mutated on disk. Those gaps plus the undocumented `filename` parameter leave an agent short of a fully confident call, despite solid coverage of the frame argument.

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 0%, so the description carries the full burden and it only partially delivers: `frame` is well specified (1-based, must exist, error behavior on out-of-range), but `filename` — the required target file — is never mentioned or explained. Half the parameter surface is still undocumented.

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 (duplicate an existing frame) and adds the key behavioral detail that the copy lands immediately after the source. It is implicitly distinguishable from siblings like add_frame, remove_frame and move_frame, but never names or contrasts them explicitly.

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 a real precondition — the target frame must already exist and out-of-range values are rejected with the valid range rather than clamped — which tells the agent when this call is legal. However, it offers no routing guidance among alternatives such as add_frame (for a blank frame) or copy_cel/duplicate_layer, leaving the choice of tool to inference.

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