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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description is free to add the genuinely new and decision-relevant fact: invocation costs $0.01 USDC via x402, meaning an agent must handle payment. That is meaningful context beyond structured fields. It still omits what the response looks like or how confident the origin inference is, keeping it out of 5 territory.

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?

Three short sentences, front-loaded with the core purpose, then use cases, then the critical cost note. No filler. The 'Name origin:' prefix lightly duplicates the title but serves as a scannable lead.

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 single-parameter tool with full schema coverage and annotations, the description is close to sufficient, but with no output schema it should say what comes back — a country code, a cultural label, a confidence score — so the agent can chain correctly. That gap is the main omission.

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?

Only one parameter and the schema documents it fully (100% coverage, with an example like 'Pierre Bonaparte'). The description adds no meaning beyond the schema — no guidance on name format, single vs. full name, or ambiguity handling. Baseline 3 is appropriate when the schema carries the load.

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: 'identifies the likely country or cultural origin of a person's name.' An agent can immediately tell this apart from siblings like interzoid_identify_language or interzoid_gender, though the description never explicitly contrasts with them.

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?

Names three application contexts (demographic analysis, localization, marketing segmentation), which implies when to reach for it, but gives no exclusions or named alternatives (e.g., when to use interzoid_official_name instead). Usage is inferred rather than directed.

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