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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, covering the safety profile. The description adds useful behavioral context by specifying sort order ('newest first') and the fields returned, though it omits pagination limits, default behavior, and filtering semantics.

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?

The description is very short and avoids repetition, but it is a sentence fragment that front-loads a resource phrase rather than an action. It is appropriately sized for a list tool but under-specified in structure.

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 does list returned fields, which is helpful. However, it is incomplete for a 5-parameter tool with 40% schema coverage and no required parameters: it omits input parameter explanations, usage context, and any limitations such as default/max limits.

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 40%, so the description must compensate for undocumented parameters like agent_id, direction, and follow_up_only. Instead, the description lists output fields (agent, direction, numbers, when, etc.) and never explains what any input parameter does or how filtering works.

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 ('Voice-agent calls') and lists returned fields, so an agent can infer this is a list operation. However, it uses a noun phrase rather than a verb and does not differentiate from the sibling get_call, leaving the action ambiguous.

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 description provides no when-to-use guidance, no alternatives, and no exclusions. It only states ordering ('newest first') and output fields, so an agent must guess when this tool is preferred over get_call or other call-related siblings.

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