asa_optin_txn

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

The description discloses two key behaviors: the transaction is unsigned and involves a 0-amount self transfer. With no annotations provided, it carries the full burden, but it omits details like return format, signing requirements, or side effects. It provides some insight but not comprehensive transparency.

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, focused sentence with no redundant words. It is front-loaded with the core action and includes the clarifying parenthetical, making it highly concise and efficient.

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 transaction builder with 4 well-documented parameters, the description is adequate but minimal. It lacks explicit mention of the return value (though 'build' implies an unsigned transaction) and provides no usage context beyond the basics. Given no output schema, the description should do more to explain the output, but the current text meets the minimum viability.

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?

All 4 parameters have schema descriptions (100% coverage), so the baseline is 3. The description adds no additional parameter-specific meaning, which is acceptable since the schema already documents sender, assetId, network, and note sufficiently.

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: to build an unsigned ASA opt-in transaction, specifying the verb 'build' and the resource 'ASA opt-in'. It also clarifies it's a 0-amount self transfer, distinguishing it from transfer and closeout transaction builders.

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?

Usage is implied: the tool is for opting into an ASA. However, there is no explicit guidance on when to use this instead of asa_transfer_txn or asa_closeout_txn, nor any prerequisites or exclusions. The context is clear but not elaborated.

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