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 10-minute price lock, states it is free, and describes the return content. It also instructs the agent to always show the price and recipient to the human, which is behavioral guidance. However, it does not mention side effects, error behavior, or any prerequisites (e.g., authentication). It provides useful context but lacks comprehensive behavioral disclosure.

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 concise sentences with zero waste. The core action and time limit are front-loaded, followed by the output and a critical safety instruction. Every sentence earns its place, and the structure is clear 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?

This is a complex tool with 9 parameters, nested objects, and no output schema. The description is minimal, covering only the high-level purpose and one safety instruction. It does not explain how to construct requests, handle nested fields, or interpret results. While the schema covers parameter semantics, the description lacks operational context, making it incomplete for an agent to use correctly without additional guidance.

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 description coverage is 78%, so the schema already documents most parameters. The description does not add any parameter-specific meaning; it only mentions 'one purchase' without elaborating on fields. The baseline for high coverage is 3, and the description adds no extra value beyond that.

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 action: 'Lock a price (10 minutes) for one purchase.' It also specifies the key outputs (quoteId, exact USDC price, what will be delivered). This is a specific verb-resource pair and distinguishes it from 'buy' by focusing on price locking rather than execution. However, it does not explicitly contrast with sibling tools, so it lacks full differentiation.

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 implies usage before buying ('ALWAYS show the human the price... before buying') but does not explicitly state when to use quote versus buy or other siblings. No exclusions or alternative tool references are provided. The guidance is implicit, not explicit, so the agent must infer the context.

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