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

Annotations already establish readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered structurally. The description adds the scoping detail that results are limited to the authenticated account's agents, but says nothing about default result counts, pagination behavior, or cost, which are left 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 short sentences with no filler, and the core action is front-loaded before the clarifying detail. Slightly spare rather than padded, which suits a simple list tool.

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?

An output schema exists and all three parameters are documented, so the description does not need to explain return values or argument formats. For a read-only list tool with full annotation coverage, only the missing explicit usage guidance keeps this below 5.

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, offset, and business_id are already fully documented in the schema, including defaults and bounds. The description adds no parameter meaning beyond that, making the baseline 3 correct.

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 the KaiCalls agents') scoped to 'the authenticated account'. The second sentence clarifies what the listing reveals (whether a secretary is already answering calls), which helps an agent distinguish it from sibling list_* tools, though it never names those siblings 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 mention of 'whether this business already has a secretary answering its calls' implies a setup/onboarding use case, but there is no explicit when-to-use guidance, no prerequisites, and no named alternative such as get_business_info or get_activation_status. Usage is inferable rather than stated.

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