production.facial_validate_lipsync

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=true), the description discloses important behavioral traits: it is plan-first with apply=false by default, the facial reference is an immutable plan.json, candidates are new Actions evaluated through NLA tracks, the body Action is never modified, and speech input requires explicit timed phonemes/visemes. These are substantive additions that help an agent understand side effects and input requirements.

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 compact but dense with jargon and run-on clauses. It front-loads some key constraints, but phrases like 'M7 facial unit' and 'Evidence-based semantic mapping (never names only)' are cryptic without further explanation, making the structure less accessible than it could be.

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?

The description covers important domain constraints (plan/apply behavior, immutable facial reference, NLA-track evaluation, phoneme timing requirement), and an output schema exists. However, for a 6-parameter tool with 0% schema coverage, it omits parameter guidance and does not clearly route the agent relative to many sibling facial tools, leaving the definition only partially complete.

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?

The schema has 6 parameters with 0% description coverage, so the description must compensate. It only explains two aspects: apply defaults to false and facial is an immutable plan.json reference. It says nothing about brief, intent, options, object_name, or how timed phonemes/visemes are supplied, leaving most parameters 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?

The description names the tool as 'M7 facial unit' and mentions evidence-based semantic mapping, but never plainly states that it validates lip-sync. An agent can infer validation from the tool name, yet the description itself does not provide a clear verb+resource statement or distinguish it from siblings like facial_generate_lipsync or facial_analyze_lips.

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 some operational context ('plan first, apply=false by default'; 'Speech needs explicit timed phonemes/visemes'), but it does not say when to use this tool versus related tools such as facial_generate_lipsync, facial_analyze_lips, or facial_review. No exclusions or explicit alternatives are provided.

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