production.facial_generate

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

Annotations indicate a non-destructive write operation (readOnlyHint=false, destructiveHint=false). The description adds valuable context: it defaults to a plan-only mode (apply=false), creates new candidate Actions without modifying the body Action, requires timed phonemes for speech, and keeps technical QA separate from artistic review. These details go beyond the annotations and help an agent understand the tool's behavior.

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 dense paragraph that starts with a non-informative label. While it is not excessively long, it is not front-loaded with the tool's purpose, and the structure makes it hard to quickly extract key information. Each sentence contains some useful content, but the overall flow could be improved.

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 complex tool with seven parameters, zero schema descriptions, and an output schema, the description is insufficient. It does not clearly state what the tool does, fails to explain most parameters, and lacks guidance on alternatives. An agent would struggle to invoke this tool correctly based on the description alone.

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, but it only clarifies two of seven parameters: 'apply=false by default' and 'facial is the immutable plan.json reference'. The other parameters (brief, intent, options, object_name, operation_id) are not explained at all, leaving significant gaps.

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 opens with a label and unit identifier ('facial_generate: M7 facial unit') rather than stating a clear verb+resource. It hints at creating candidates but never explicitly says 'generates facial animation' or distinguishes itself from the many specific facial generation siblings (e.g., facial_generate_blink, facial_generate_expression).

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?

It gives a procedural note ('plan first, apply=false by default') and a condition for speech ('Speech needs explicit timed phonemes/visemes'), but provides no guidance on when to choose this tool over the numerous other facial generation tools. There is no explicit when-to-use or when-not-to-use, and no mention of alternatives.

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