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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely useful context beyond that: cursor-based paging with a 20-per-page default and an explicit warning that the payload contains personal data. It omits auth/permission requirements and rate limits.

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 short clauses with zero filler: scope and returned fields first, then paging/filtering, then the PII warning and endpoint. Everything is front-loaded and each sentence earns its place.

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 correctly compensates by enumerating returned fields, and it covers pagination, filter dimensions and the PII caveat. What remains missing is routing guidance against search_customers and any note on permissions, which for a read-only list tool is a minor gap.

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 86%, so the schema already documents desc, limit, the date params, location_id and start_after. The description restates the filterable dimensions (location, external id, date) and the page size default but adds no syntax or format detail the schema lacks, so the baseline 3 applies.

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 and resource ('List customers') and enumerates the returned fields (name, phone, e-mail, tags, last visit, created/updated), which is more than a restatement of the title. It does not, however, position itself against the obvious sibling waitwhile_search_customers or waitwhile_get_customer, so an agent must infer the boundary.

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 conveys implied usage through its filter list (location, external id, created/updated date) and paging behavior, so an agent can infer when it is applicable. It never explicitly says when to choose this over search_customers or get_customer, nor does it state any prerequisites.

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