shape_key.set_value

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

Annotations already indicate readOnly=false, destructiveHint=true, and idempotentHint=true. The description adds meaningful context beyond those hints by specifying the exact shape-key constraints and requiring an active transaction. It accurately aligns with the annotations and clarifies that this is a mutating, transactional value overwrite.

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 description is a single focused sentence with no redundant words. It front-loads the action and resource, then adds the key constraints. Every phrase earns its place.

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 destructive, idempotent mutation with eight required parameters and zero schema descriptions, the description is too thin. It does not explain the expected-identity concurrency mechanism, idempotency semantics, or consequences of the destructive hint, leaving significant gaps for an agent attempting correct invocation.

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 must compensate for explaining the eight required parameters. It only implicitly maps to transaction_id, object_name, shape_key_name, and value; it leaves expected_object_identity, expected_shape_key_identity, expected_scene_generation, and idempotency_key completely unexplained, which an agent needs to invoke the tool correctly.

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 description states a specific action ('set'), a precise resource ('one exact non-Basis, non-driven mesh shape key'), and the semantics ('absolute value inside the active transaction'). It clearly distinguishes this tool from broader siblings like object.set and material.set_input.

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 conveys clear usage context: the operation requires an active transaction and applies only to non-Basis, non-driven shape keys. It does not explicitly mention alternative tools or when not to use it, but the scoping is strong enough for an agent to recognize the intended situation.

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