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

With no annotations, the description carries the full burden and does disclose useful traits: authentication is not required ("Credential: none"), the call is free, and the response includes editions, official sources and applicability notes. It still omits read-only/pagination/rate-limit behavior, but the auth and cost disclosures are concrete added value.

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?

Four short sentences with no filler, and the result content plus credential/cost facts are front-loaded. The first-person "I want to research..." framing is a slight structural oddity that reads more like user intent than a tool spec, but it costs little.

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 one-optional-parameter tool with no output schema, the description adequately covers return content (editions, sources, applicability notes) and access requirements (no credential, free). The remaining gap is sibling disambiguation against read_international_law/research_international_law.

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 single parameter "q" has 0% schema description coverage, so the description must compensate and does not. "Searches or lists" hints that an optional query exists, but there is no mention of the 240-character cap, query syntax, or what a queryless call returns.

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 names concrete resources (UNIDROIT contract principles, UNCITRAL texts, New York Convention) and states both verbs (searches or lists), so the agent knows what the tool returns. It never distinguishes itself from the near-identical siblings read_international_law and research_international_law, which is the main clarity gap.

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 opening line implies a usage scenario (researching rules relevant to a deal or dispute), which gives context for when to reach for it. But there are no explicit when/when-not statements and no routing to alternatives, even though two similarly named siblings exist.

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