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

No annotations are provided, so the description carries the burden. It discloses that this is a compatibility alias and that onchain_lookup should be preferred, which is useful contextual behavior. However, it does not mention other behavioral aspects like return format, error handling, or read-only nature, though the name and schema imply a simple lookup.

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 sentence that packs purpose and usage guidance efficiently. Every word earns its place, and the most important information (prefer onchain_lookup) is front-loaded.

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?

This is a simple metadata lookup tool with a well-documented schema. The description tells the user it is a compatibility alias, points to the preferred tool, and the schema covers parameters. While it does not explain return values or limitations, the low complexity and alias nature make it reasonably complete.

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 description coverage is 100% with both 'address' and 'chainId' described clearly. The description adds no parameter-specific information, but the schema already fully documents each parameter, so the baseline of 3 is appropriate.

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 identifies the tool as a compatibility alias for onchain_lookup contract metadata, making it clear that it retrieves contract information. It does not use an explicit verb like 'get', but the phrase 'contract metadata' combined with the tool name conveys the function. It distinguishes from siblings by naming the preferred alternative, onchain_lookup.

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 explicitly says 'Prefer onchain_lookup for new clients', giving clear when-not-to-use guidance and naming the alternative. This is exactly the kind of actionable directive that helps an agent choose between this tool and its sibling.

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