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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description goes further by disclosing the sort order (newest first) and cursor pagination via metadata.next_cursor, which is genuinely useful behavior beyond the annotations, though it says nothing about rate limits or result size limits beyond the schema.

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?

Three compact sentences, front-loaded with the resource and returned fields, then filtering options, then pagination. Every sentence carries information and none is wasted.

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 no output schema, the description covers the returned fields, ordering, filter dimensions, and pagination mechanism, and annotations cover the safety profile. An agent has everything needed to call it correctly.

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 the schema already documents all six parameters including enum values and limits. The description only restates which filters exist (email, state, updated_at) without adding syntax or format detail beyond the schema, which is the expected baseline.

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?

Names a specific verb and resource ('List loyalty-program customers') plus the returned fields (points balance, state, VIP tier id) and the default ordering. It is clearly distinguishable from the sibling smile_get_customer single-record fetch.

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 states the three selection modes: exact-email lookup, filter by state, or filter by last-updated time. It gives clear usage context but never names smile_get_customer as the alternative for single-record retrieval, so no explicit exclusion is offered.

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