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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds useful behavior beyond that: pagination via next_cursor, the matching fields for search, and the note that email may be a comma-separated list. It omits ordering guarantees and page-size behavior, keeping it just shy of a 5.

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?

Front-loads the returned resource and fields, then packs search usage, archived behavior, and cursor semantics into tight sentences. Dense but no filler; slightly cramped rather than bloated.

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?

No output schema exists, so the description carries the burden of describing return contents, which it does (contact, email, phone, mobile, address, sites). Pagination and search semantics are covered; ordering and empty-result behavior are not, a minor gap for a list tool.

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 coverage is 75% and the description reinforces the meaning of `search` (matches name/contact/email/phone), `archived` (lists archived instead), and `cursor` (pass next_cursor back). Only `limit` is left to the schema, which is self-evident, so the description adds real value on the non-obvious params.

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 (lists) and resource (customers) plus the returned fields (contact, email, phone, mobile, address, sites). The opening sentence establishes exactly what the tool produces, distinguishing it from mutation siblings like create_customer and unrelated list_* tools.

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?

Explicitly says to use `search` to find a customer_id before creating a job or quote, and clarifies that `archived` switches to archived customers. It gives clear positive usage context but does not explicitly exclude or contrast against all sibling list tools (e.g., list_quotes/list_jobs), so it stops short of a 5.

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