Moralis MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the tool lists 'active' approvals, implying a read-only operation, but doesn't specify if it's paginated (though the schema hints at pagination with 'limit' and 'cursor'), what the output format is, rate limits, or any error conditions. This leaves significant gaps in understanding how the tool behaves beyond basic functionality.

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 description is a single, efficient sentence that directly states the tool's purpose without unnecessary words. It's front-loaded with the core action and resource, making it easy to parse quickly. There's no wasted verbiage, earning a top score for conciseness.

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?

Given the tool's complexity (querying blockchain data with 4 parameters) and lack of annotations and output schema, the description is insufficient. It doesn't explain the return format, pagination behavior, or potential errors, which are critical for an AI agent to use the tool effectively. The high schema coverage helps with inputs, but overall context is incomplete.

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 schema description coverage is 100%, meaning all parameters are documented in the schema itself. The description adds minimal value by implying the 'address' parameter is for a wallet and the output relates to ERC20 tokens, but it doesn't provide additional context like format examples or edge cases beyond what the schema already states. This meets the baseline for high schema coverage.

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 clearly states the tool's purpose: 'List active ERC20 token approvals for a wallet, showing which contracts have access.' It specifies the verb ('List'), resource ('active ERC20 token approvals'), and target ('wallet'). However, it doesn't explicitly differentiate from sibling tools like 'evm_getwallethistory' or 'evm_getwalletstats' that might also involve wallet data, so it doesn't reach the highest score.

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 description provides no guidance on when to use this tool versus alternatives. It doesn't mention any prerequisites, exclusions, or specific contexts for usage. For example, it doesn't clarify if this is for security audits, transaction analysis, or other scenarios, leaving the agent without usage direction.

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