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

The description fully discloses the tool's behavior: it is read-only, cannot move or spend coins, requires a short-lived token from the user, and returns a specific error message for invalid tokens. This is comprehensive given no annotations are provided.

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 extremely concise, using three sentences to cover purpose, usage instructions, and error handling. It is front-loaded with the core functionality and avoids any fluff, making it easy for an agent to parse quickly.

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?

There is no output schema, but the description specifies the return expectation (balance plus expiring coins summary and error object for invalid tokens). It covers the authentication mechanism, error recovery, and the tool's limitations, making it fully complete for an agent to select and invoke correctly.

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 single parameter 'wallet_token' is already documented in the schema, but the description adds crucial context: how to obtain it (user must generate in the app), its expiration (~10 minutes), and what to do if it's invalid. This adds significant value 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 it is a read-only wallet summary for SOMA Coins, including balance and expiring coins. It distinguishes itself from siblings by emphasizing it cannot claim or redeem coins, and that there are no such tools available, making its purpose unambiguous.

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 instructs the agent to ask the user for a wallet token generated in the app, notes the token expires in ~10 minutes, and explains the expected behavior when the token is invalid. It also clarifies it should not be used for claiming or redeeming coins, providing clear usage boundaries.

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