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

Annotations already declare readOnly/openWorld, so the bar is lower and the description clears it by disclosing the residential-proxy access path and the x402 payment model ($0.01 USDC per successful call on Base/Solana/Arc, failed calls free) — material auth/cost behavior an agent must plan around. It says nothing about rate limits, retries, or caching, which keeps it from a 5.

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?

Front-loaded with the source and scope, then fields, filters, and pricing in a compact block. The field enumeration is dense but each item signals what the agent will receive; it borders on a run-on single sentence but wastes no clauses.

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 an output schema present, return shape needn't be described, and the description covers source, scope, amendment coverage window (2014-2025), filters, and payment. Minor gaps remain around behavior when a country filter matches nothing and whether results are paginated or full.

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 baseline is 3, but the description adds real semantics: instrumentId is not just an MLC id but the gateway to other ILO conventions, and country is explicitly a name filter rather than a code. That meaning exceeds the schema's terse field descriptions.

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+resource: ILO MLC 2006 ratifications from NORMLEX, and enumerates exactly what is returned (ratification dates, status, declarations, country links, amendments with entry-into-force). This is clearly distinguishable from the freight/customs-oriented siblings, none of which cover ILO labour conventions.

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 closing clause gives filter guidance ('Filter by country; other ILO conventions via instrumentId'), which implies how to narrow results, but there is no statement of when to prefer this tool, prerequisites, or any named alternative. Usage is inferable rather than explicit.

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