list_custom_tokens

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

With no annotations provided, the description carries the full burden. It explicitly states 'Public data; no secrets involved,' which is helpful for safety. It does not mention any destructive behavior or side effects, but for a read-only list operation, this is adequate.

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 concise with two sentences, front-loading the main purpose. It includes usage examples and parameter explanation without unnecessary verbosity. Every sentence serves a purpose.

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 tool with one optional parameter and no output schema, the description is fairly complete. It covers purpose, usage, safety, and parameter behavior. However, it does not describe the return format or any pagination, but these may be implied.

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% with one parameter. The description adds value by explaining that omitting 'account_id' lists across all accounts, which is not explicitly stated in the schema. This provides context 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 what the tool does: 'Lists custom ERC-20 tokens tracked by MetaMask accounts.' It uses a specific verb ('lists') and resource ('custom ERC-20 tokens'). This distinguishes it from sibling tools like 'add_custom_token' and 'remove_custom_token' which perform different actions.

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 example user queries ('which custom tokens am I tracking', 'show my project tokens') to guide when to use the tool. It also mentions 'Public data; no secrets involved' indicating safety. However, it does not explicitly state when not to use it or suggest alternatives.

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