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

readOnlyHint=true already declares the safety profile, so the description's main added value is the field-level inventory of what each shift record contains — genuinely useful since no output schema exists. It does not disclose pagination behavior, default/maximum page semantics, or rate limits, but for a read-only list with a fully described schema that is a modest 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?

Two sentences, front-loaded with the resource and its contents, with the API endpoint mapping tucked at the end. The long field enumeration is dense but each item is substantive, not filler.

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, 5-parameter list tool with full schema coverage, the description covers what the tool is and what it returns, compensating for the absent output schema. The only omissions are pagination mechanics and any note about ordering or volume of results, which are minor here.

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%, so limit, cursor, store_ids and both created_at bounds are already fully documented in the schema. The description adds no filter syntax, timezone, or paging guidance beyond that, so the 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?

States a specific verb (List) and resource (cash-register shifts) and then enumerates the exact contents returned — cash, gross/net sales, refunds, discounts, taxes, per-payment-type totals, pay-in/pay-out movements. The 'end-of-day view' framing plus the 'Loyverse: GET /shifts' mapping makes it unmistakable against the other loyverse_list_* siblings, which cover different resources.

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 'the end-of-day view' implies the scenario (closing/reconciling a register), which is useful implied context. However, there is no explicit when-to-use guidance, no statement of what it is not for, and no pointer to an alternative sibling for a different kind of shift or sales query.

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