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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds valuable behavioral context: the response is heterogeneous and requires reading item_type for each item, reimbursement items carry specific temporal and monetary fields, and time_left should be surfaced prominently when expiring items are relevant. No contradiction with annotations exists.

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 efficiently structured: the first sentence identifies the feed, the second unpacks the mixed item types and field contract, and the third gives actionable display guidance. Every sentence earns its place, with no filler or repetition.

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 must convey the return contract, and it does so well for reimbursement items and acceptably for gift_code items. However, it omits behavior around pagination, ordering, default scope, and how brand_uuid affects results. These are meaningful gaps for a list tool, though the simple two-parameter shape and read-only annotations keep the tool callable.

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 bears responsibility for explaining inputs. It does not describe `scope` (active/upcoming/ended/all), `brand_uuid`, defaults, or how scope relates to starts_at/ends_at/time_left. The enum values and parameter names are somewhat self-explanatory, but the description never clarifies optionality or filtering behavior, so it fails to compensate for the missing schema documentation.

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 clearly identifies the resource ('The creator's gifts feed') and the operation (a MIXED list requiring item_type checks). The title 'List gifts' and tool name align, and the mention of reimbursement items and gift_code items distinguishes it from generic list tools. However, it does not explicitly name a sibling tool to differentiate from, so it stops just 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?

The description provides context about what the feed contains but gives no explicit guidance on when to use this tool versus alternatives such as split_get_reimbursement, split_activate_reimbursement, or split_list_campaign_bonuses. There is no 'use when' or 'when not to use' statement, leaving the agent to infer selection criteria from the resource name alone.

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