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

With no annotations supplied, the description carries the full behavioral burden, and 'Public read' usefully discloses that no auth or subscription is required and that the call has no side effects. It does not cover failure behavior (unlisted agent) or rate limits, but the key safety profile is stated explicitly.

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, zero filler, with the core capability front-loaded and the access/scope caveat second. Every clause 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 two-parameter read tool with no output schema, the description compensates well by naming the fields returned in the listing object. It is not exhaustive about the response shape or empty-listing behavior, but an agent has enough to call it correctly.

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 100%, so both the 'chain' enum (including 'central') and the agentId integer are already documented in the schema. The description's note about negative agentIds for centralized agents reinforces but does not meaningfully extend the schema, matching the baseline of 3.

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 opens with a specific verb+resource ('Get the marketplace listing for an agent') and enumerates the returned attributes (visibility, pricing type, USD price, payment link), so the agent knows exactly what it retrieves. It does not explicitly contrast with siblings like actora_listing_set, actora_listing_delist, or actora_listing_price, so it falls short of full sibling differentiation.

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?

'Public read — works for on-chain agents and centralized (negative) agentIds' implies the read-only inspection use case, and the mention of negative agentIds signals applicability to off-chain agents. However, it never states when to prefer this over actora_listing_price or actora_listing_set, nor what happens if no listing exists, leaving usage largely inferred.

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