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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful domain context about what an agent contains and that it is scoped to the calling user, but says nothing about result volume, pagination, or ordering.

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 the action front-loaded and the explanatory sentence immediately after. Every clause contributes either the resource identity or the definition of an agent, with no filler.

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 zero-parameter read tool with annotations covering safety, this is nearly complete: it says whose agents are returned and what an agent is composed of. The only gap is that with no output schema, it could hint at the per-agent fields (e.g. id, name) an agent would receive.

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?

The tool takes zero parameters, so there is no parameter meaning to add beyond the schema. Baseline 4 applies; the description correctly avoids inventing filtering options the tool does not support.

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 Phone Bud user's configured voice agents') and clarifies the object's scope as user-owned. It implicitly separates itself from list_campaigns/list_contacts by naming a distinct resource, though it never explicitly contrasts with a sibling.

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?

Usage is only implied: an agent would infer this is the discovery step before create_agent, update_agent, or make_call. There is no explicit when-to-use or when-not-to-use statement, and no named alternative for fetching a single agent.

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