set_morph_target

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

Annotations only declare the mutation/idempotency profile; the description adds the critical behavioral facts that the change is ephemeral, is not persisted to source, is logged in pending_changes, and has a defined undo path via revert_changes. That is precisely the context an agent needs before calling a live-preview mutation.

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 sentences, no filler, and the constraint banner is compact. The only structural weakness is that the actual purpose statement trails the banner, so the first thing the agent reads is a caveat rather than what the tool does.

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 5-parameter tool with fully described schema and no output schema, the description covers the important non-obvious behavior (ephemerality, undo, pending_changes). It leaves minor gaps such as behavior when the named mesh or morph target cannot be resolved.

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 every parameter (name, uuid, index, influence, targetName) is already documented in the schema. The description adds nothing about parameter interaction (e.g., how the mesh is identified or influence range beyond the schema's "0-1"), so the baseline of 3 applies.

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?

"Set a morph target influence" is a specific verb+resource that separates it from the read-only sibling morph_targets. However, the purpose sentence is placed after the preview banner, and the description never explicitly names morph_targets as the read counterpart, so sibling differentiation is implicit rather than stated.

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 clear operating context: browser-only change, not written to source, lost on reload, recorded in pending_changes, and undoable via revert_changes. It stops short of an explicit when-not rule or a named alternative for permanent edits, but the workflow it belongs to is unambiguous.

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