Merge people

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

Annotations cover the safety profile (readOnlyHint=false, idempotentHint=false, openWorldHint=true), and the description adds genuinely non-obvious behavior: that the merge also affects other users in the cluster group and that name/birth-date overrides are skipped. It does not disclose what happens to the non-surviving people records, which is the biggest remaining behavioral gap.

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?

Body is tight and front-loaded: purpose, then ordering rule, then side-effect rule. The leading 'Merge people' line merely restates the title and the trailing 'Immich operation: POST /people/merge · tag: People' is boilerplate, so a small amount of the text does not earn 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 single-parameter mutation with no output schema, the description covers purpose, ordering semantics, and cross-user side effects. It is close to complete; only the fate of the merged-away people and any auth/permission requirement are unstated.

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 coverage is 100% but the schema only labels the array as 'ids (request body)' with uuid items; the description adds the critical ordering contract (first defined name/birth date wins) that an agent cannot infer from the schema. That is real semantic value beyond the structured field.

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?

States a specific verb (merge) and resource (people), plus the scope of the operation (an ordered list collapsed into a single person). It does not explicitly distinguish itself from the close siblings immich_merge_person_legacy or immich_update_people, so it stops short of a 5.

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?

Usage is implied by the description of ordering semantics and the cluster-group auto-merge, but there is no explicit when-to-use guidance, no mention of when to prefer immich_merge_person_legacy or immich_update_people, and no stated preconditions (e.g. ownership or admin requirements).

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