purchase-history

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description usefully discloses the output shape (total spent, average price, per-store breakdown, recent purchases), which goes beyond the annotations, but since an output schema exists this is partially redundant and no other behavioral traits (pagination, empty-result behavior) are added.

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 tight sentences with no filler, and the purpose is front-loaded before the filter list and return summary. Slightly over-specifies outputs that the output schema already carries.

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, four-optional-parameter search tool with a full output schema, the description covers purpose, filters, and result contents adequately. The only gap is absence of any cross-tool routing guidance, which a multi-sibling environment would benefit from.

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 all four parameters are already documented in the schema, including the YYYY-MM-DD date format. The description notes the date format again but adds no syntax beyond what the schema provides, establishing the baseline of 3.

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 (Search) and resource (purchase history) plus the added value (spending summary), so an agent knows exactly what the tool returns. It does not, however, differentiate itself from plausible siblings like consumption-history or cellar-stats, leaving the selection boundary implicit.

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 enumerates the available filters but never says when to use this tool versus consumption-history, cellar-stats, or recent-deliveries. No prerequisites, no exclusions, no routing guidance — the agent must infer applicability from the name alone.

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