Get venues a user has checked in at

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, and the description's 'Read-only' is consistent with them (no contradiction). Beyond the annotations, it adds genuinely useful behavior: default ordering ('most recent first'), return aggregation shape ('per-venue check-in counts'), and the fallback behavior of using the configured account when username is omitted. It does not describe the per-venue record fields, but for a read-only list tool with strong annotations this is solid.

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?

Four short sentences, purpose first, with zero filler: purpose+ordering+aggregation, capability scope, account targeting, and a one-word safety confirmation. The 'Read-only' repetition of the annotation is minor and harmless. Every sentence carries distinct, decision-relevant 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?

For a read-only list tool with 4 fully documented optional parameters, strong annotations, and no output schema, the description covers purpose, ordering, aggregation shape, paging/sorting capability, and own-account targeting. The only real gap is that it does not explicitly route the agent away from the closely related untappd_user_checkins, which would have made it fully 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?

Schema description coverage is 100% — every parameter (sort, limit, offset, username) already has defaults, ranges, and meaning documented. The description's 'most recent first' and 'Omit username for your own account' merely restate what the schema's parameter descriptions already say, so it adds no material semantics beyond the structured data. Baseline 3 is appropriate.

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 first sentence states a specific verb + resource: 'Get the venues a user has checked in at', and adds distinctive detail ('most recent first, with per-venue check-in counts'). This is clear and somewhat distinguishes it from siblings like untappd_user_checkins (raw checkin events) and untappd_venue_info (single venue details), but the differentiation is implicit through the aggregation wording rather than stated outright.

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 useful usage context: 'Supports sorting and paging' signals when this tool is appropriate, and 'Omit username for your own account' is an explicit usage rule. However, it never addresses alternatives — notably untappd_user_checkins, the closest sibling, is never mentioned, and there is no when-not-to-use guidance.

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