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

Annotations already declare readOnlyHint and closed-world, so the safety profile is covered; the description contributes the substantive scope constraints (US-only shipping, size/file limits, turnaround) that shape what answers are possible. It does not state whether the facts are static documentation versus live data, which is the one behavioral detail an agent might want. No contradiction with the read-only annotation.

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 content list is front-loaded in one dense sentence using a parallel structure, with the usage routing in a second sentence. Every clause maps to a distinct fact category, though the enumeration is long enough that it reads as a checklist rather than a sharp summary.

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 and no output schema, the description carries the burden of telling the agent what comes back, and it does so by cataloguing the seven fact categories. The only missing piece is the return shape (prose versus structured sections), which is minor for a static info tool.

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?

Zero parameters, so there is nothing to disambiguate and the baseline is 4. The description correctly signals a parameterless lookup by presenting the tool as a fixed fact sheet rather than a query interface.

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 enumerates precisely what the tool returns: printing capabilities, US shipping scope, pricing formula with examples, colors, size/file limits, turnaround, and ordering steps. That is far more specific than the title 'Service facts and prices'. It stops short of a crisp verb framing (it never says it returns a static knowledge document), but the content scope is unmistakable.

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 gives explicit trigger questions ('where can I get something 3D printed', 'how much does 3D printing cost'), which tells the agent when to reach for it. The gap is that it does not distinguish itself from the sibling price_quote, even though it claims the 'how much does 3D printing cost' intent — the agent must infer that this returns a generic formula while price_quote produces a specific number.

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