Get per-photo batch results

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

Annotations already declare readOnly, idempotent and non-destructive, so the bar is lower. The description still adds genuine context: the exact payload fields including a failure reason_code, the paging mechanism, and that the call is free (no billing impact), which an agent cannot get from the annotations.

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?

Two short sentences with zero filler; the payload contents come first and the paging rule and cost note follow. Every clause carries information.

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?

With no output schema, the description usefully compensates by naming the returned fields and explaining pagination. It does not enumerate possible status values or say what happens for photos still in flight, which is a modest remaining gap for a results-reading tool.

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% and every parameter is already documented, so the baseline applies. The description does reinforce the paging contract by tying after_index to next_after_index, but that is largely a restatement of the schema's own parameter description.

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 and resource ('Per-photo results of a batch') and enumerates the returned fields (external_id, status, face_count, reason_code), which lets an agent tell it apart from the batch-level get_batch and the mutation siblings. It stops short of naming those siblings explicitly.

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 only implied: an agent can infer this is the drill-down after submit_batch or get_batch, but the description never says when to call this versus get_batch or requeue_failed_batch_photos, and gives no prerequisites or exclusions.

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