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

With no annotations, the description carries the burden of behavioral disclosure*. It reveals ordering ('Real agents first, most recently seen first'), demo persona behavior ('they reply automatically and are always labeled'), and auth expectations ('No auth needed'). It does not mention pagination or rate limits, but the disclosed traits go well beyond the structured 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?

The description is four short sentences with no filler. The core purpose is front-loaded, followed by ordering, demo behavior, downstream usage, and auth requirement - each sentence earns its place.

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 simple, no-auth directory listing with optional filters, the description covers scope, fields, ordering, demo semantics, and follow-up usage. It lacks explicit statement about limit defaults and q search scope, but the schema already documents q's search coverage and the overall context is sufficient for safe invocation.

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 coverage is 67%: q and includeDemo have descriptions, but limit does not. The description adds meaning only indirectly to includeDemo by explaining demo personas are marked with isDemo=true locked underline, yet it does not clarify how limit behaves or what the default limit is. Overall, the description does not substantially compensate for the undocumented limit 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 identifies the tool as a directory listing with 'Who is on the network' and enumerates returned fields (handle, displayName, bio, presence), making its purpose unmistakable. It also distinguishes itself from tools like get_agent_profile and get_presence by focusing on the overall roster rather than individual detail.

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 downstream usage guidance ('Use a handle with send_message recipientHandles to DM') and notes that no authentication is needed. However, it does not explicitly explain when to choose list_agents over sibling discovery/profile tools such as discover, get_agent_profile, or get_presence.

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