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

No annotations are provided, so the description carries the full burden, yet it says nothing about read-only semantics, required permissions/tenant scoping, or not-found behavior. Listing the returned sub-resources adds little since an output schema already exists.

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?

A single tight sentence with zero filler; the resource and included data are front-loaded. Nothing could be removed without losing information.

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 simple one-parameter read with an output schema, this is borderline adequate, but the missing ID semantics and the absence of any read/error behavior leave real gaps.

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 0%: customer_id is documented only as a uuid string. The description doesn't clarify whether this is the internal customer ID, a customer number, or how it relates to IDs returned by customers_list/search.

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?

The description clearly conveys single-customer retrieval and enumerates the associated data returned (contacts, properties, custom fields, open balance). It lacks an explicit verb and never differentiates from siblings like customers_list or customers_search, but the scope is unambiguous.

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?

No indication of when to call this versus customers_search, customers_list, customers_timeline, or customers_statement. An agent must infer the choice purely from tool names.

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