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

The annotations already declare readOnlyHint, idempotentHint, non-destructive behavior, and closed-world scope. The description adds useful behavioral context by listing returned fields and noting that an API key unlocks additional risk and creator data, though it does not discuss error behavior or missing-result cases.

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 two compact sentences with the primary purpose front-loaded and the usage rule immediately after. Every clause contributes actionable information.

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 simple one-parameter read-only tool with complete schema coverage and annotations, the description supplies sufficient context: what it returns, when to use it, and the direct alternative. No output schema exists, so the field list is especially helpful.

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%, and the schema already documents the single id parameter with examples. The description reinforces that the id must come from search and gives the "<chain>:<address>" format, but adds little beyond the schema.

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 that this tool fetches a full check_token result for an id returned by search, and enumerates the returned fields. It distinguishes itself from search and check_token by explaining the result-id workflow versus known-address 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?

It explicitly says to use this after search and directs agents to call check_token directly for a known address. This gives both the intended sequence and the relevant alternative sibling tool.

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