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 two genuinely useful facts beyond that: customer API keys are never returned (sensitive-data scoping) and the underlying call is POST /customers/get, which explains why a write-shaped HTTP verb is used for a read. Pagination behavior is left entirely to 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?

Two tight sentences: purpose plus returned fields first, then filter keys, then the security caveat and endpoint. No filler, and the most decision-relevant information is front-loaded.

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 compensates by listing the fields a reply contains, which is the right call for a 10-parameter list tool. It is slightly incomplete in not mentioning the paging contract (offset from next_offset, page_size cap) that matters for actually retrieving all customers.

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 90%, so the schema already documents parameters well, setting the baseline at 3. The description's filter sentence only restates what the schema says ('name (contains)') rather than adding format or interaction rules, and it omits offset/page_size entirely.

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, email, address, status, customer number, salesperson), which is much richer than the title. It implicitly separates itself from get_customer via 'List', but never names the sibling explicitly.

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 filter list (name contains, state, status, modified_since) implies a browse/filter use case, but there is no statement of when to prefer this over markettime_get_customer for a single record, or over markettime_list_customer_contacts for nested data. Usage is inferable but not prescribed.

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