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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety and scope are covered structurally. The description adds value by telling the agent what the records contain (routing/queue context, answer behavior) and how pagination works. It does not mention ordering, whether held/released numbers appear, or total counts, so beyond the annotations the added behavioral context is useful but not rich.

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 sentences, front-loaded with the resource, then the alternative, then the mechanics. Every sentence carries distinct information with no repetition of the title or annotations.

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 paginated list with full schema coverage and annotations handling safety, the description covers what the tool returns and how to page. Minor omissions remain — result ordering, default page size (left to the schema), and whether inactive numbers are included — but nothing that would cause an incorrect call.

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 limit, cursor and purpose are already fully documented in the schema, making 3 the baseline. The only added semantics is the paging recipe "pass next_cursor back as cursor," which essentially restates the cursor field description. No new meaning is introduced for limit or the purpose parameter.

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 names the resource precisely ("the phone numbers the workspace owns") and even characterizes what each entry reports (queue or menu assignment, whether SautiDesk answers). It explicitly separates itself from desk_search_numbers, the closest discovery sibling. It stops short of distinguishing itself from the similarly named list_numbers sibling, so it is clear but not fully differentiated.

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?

It gives a concrete routing rule — use desk_search_numbers when the goal is to buy a number — which is exactly the ambiguity an agent would otherwise hit. It also supplies an operational instruction for paging. It offers no guidance on when this list is the wrong choice versus the plain list_numbers tool.

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