ensure_fixtures_in_look

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

With no annotations, the description carries the full burden. It does disclose the important behavioral trait that the operation is idempotent ('adding only if missing'), which is real value. However, it leaves a critical ambiguity: what happens when a fixture already exists with different values — update, ignore, or error? It also says nothing about live DMX output impact, permissions, or return 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?

A single sentence with no filler; the behavioral qualifier ('adding only if missing') is placed where it matters, right after the core action. Every word 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 mutation tool with no annotations and no output schema, the description covers the essential idempotency semantics but omits the effect on existing fixtures whose values differ, whether the change touches live output, and any confirmation of what is returned. Adequate but with a clear gap at the exact decision point an agent would hit.

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%, and each parameter (lookId, fixtureValues, channels, offset, value, lookOrder) is documented in the schema itself, so the baseline is 3. The description adds only 'with given values', which does not extend the schema's meaning.

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 a specific verb+resource ('ensure specific fixtures exist in a look') plus a scope qualifier ('adding only if missing'), which implicitly separates it from add_fixtures_to_look. It never names a sibling explicitly, so the differentiation is inferential 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 phrase 'adding only if missing' implies the idempotent use case (call when you want a guaranteed end state without duplicates, vs add_fixtures_to_look for unconditional insertion), but no alternative tool or triggering condition is stated. Usage must be inferred from the wording.

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