marketplace_info

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

Annotations already cover the read-only, closed-world safety profile, so the description adds the parts annotations cannot: it states what comes back (sources plus capabilities), clarifies configuration happens outside the tool via env vars, and warns that community-uploaded models are unverified with guidance on evaluating them. The safety advice is somewhat tangential to enumerating marketplaces, but it is still useful context beyond structured fields.

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 purpose and return value are front-loaded, followed by configuration note and sibling routing, which is a sensible ordering. The trailing safety note is paragraph-length and only loosely tied to listing marketplaces, adding a bit of bulk beyond what the tool needs.

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 parameters, no output schema, and annotations covering safety, the description does enough: it says what is returned and where configuration lives. It stops short of describing the exact shape of each marketplace entry (e.g. whether credential state or errors per source are included), which would help an agent decide when a follow-up call to marketplace_status is needed.

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 nothing for the description to disambiguate and the baseline is 4. The description correctly implies no inputs are needed, matching the empty schema.

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 and resource: shows which 3D model marketplaces are connected. It then explains the return (list of connected sources and their capabilities such as search and download support). It is clearly distinguishable from the similarly named marketplace_status and marketplace_diagnostics, which are explicitly routed elsewhere.

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?

It names both alternatives and the conditions that select them: marketplace_status for per-credential diagnostics and marketplace_diagnostics for live connectivity probes. It also tells the agent that marketplaces are configured through environment variables, implying this tool only reports and does not configure.

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