open_credit_line

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

With no annotations, the description carries the full burden. It discloses a side effect ('the server signs a borrow intent collateralized from the agent's wallet'), a prerequisite (wallet must hold deposit), and an authorization requirement (developer key). However, it does not explain the return value, reversibility, or potential failure modes, leaving some behavioral gaps.

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 and well-structured: three sentences that front-load the core purpose, then add prerequisites and authorization. Every sentence adds necessary information, with no filler or redundancy.

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?

Given the moderate complexity (4 parameters, no output schema, no annotations), the description covers purpose, prerequisites, auth requirements, and references to related tools. It could benefit from stating what the response contains, but it is adequate for an agent to understand the operational context.

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 schema provides full 100% coverage of all 4 parameters. The description adds value by linking deposit_raw to collateralization from the agent's wallet, referencing get_credit_line_bounds for valid ranges, and clarifying that max_ltv_bps and max_rate_bps are optional overrides. This enriches the schema's basic definitions.

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 function: 'Upgrade a pay-as-you-go agent to a managed credit line.' It distinguishes from siblings like create_borrow_intent by emphasizing the upgrade action and the managed credit line outcome, making the purpose specific and 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?

The description provides explicit prerequisites: the wallet must already hold the deposit (with a reference to get_funding_instructions) and advises checking get_credit_line_bounds first for valid deposit/LTV ranges. It also notes the developer key requirement. It lacks explicit alternative exclusions (e.g., 'use create_borrow_intent instead'), but the context is clear.

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