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

Annotations already carry readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely non-obvious behavior: a paid x402 call at $0.002 USDC with settlement on Base, Solana or Arc, and that failed calls are not charged — material cost information an agent must know before invoking.

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?

Content is front-loaded with identity and search capability, then the return payload, then pricing. It is a single dense block rather than scannable sentences, but every clause carries information; nothing is padding.

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, spelling out return fields is mild redundancy, but the description supplies the pieces structured data cannot: billing model, payment rails, and failure-charge policy. What is missing is sibling routing against the other carbon registries in this toolset.

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 the baseline is 3. The description earns above baseline by decoding the type-code parameter conceptually (forest carbon, landfill gas, refrigerants, orphaned wells, CCS), which the schema only exposes as bare abbreviations like FC, LGCC, REF and ORW.

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: searching ACR project records on ICE GreenTrace by text or project type, and enumerates the returned fields. It is clearly distinct from siblings by registry identity (ACR), though it never names the adjacent registries (Verra, Gold Standard, Climate Action Reserve) that an agent might confuse it with.

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?

Usage is only implied: 'search by text or project type' plus example project types tells the agent how to call it, but there is no guidance on when to choose this registry versus the sibling carbon-registry tools, nor any statement of exclusions or prerequisites.

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