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

No annotations are provided, so the description must bear the full burden of behavioral disclosure. It states the tool is 'free' and shows costs, but does not mention whether it is read-only, requires authentication, or has any side effects. This is insufficient for a tool that previews pricing.

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 very concise: three sentences that front-load the purpose and add relevant details (base cost, constraint effects, free-of-charge). Every sentence earns its place with no wasted words.

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?

While an output schema is present (so return values are covered), the description lacks context on how to specify the tool call (e.g., via tool_id) or any prerequisites. It is minimally viable but leaves gaps for a user unfamiliar with the system.

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 50%, but the tool description adds no extra meaning beyond the schema. It does not explain how parameters like tool_id or tool_kwargs are used in the context of cost preview. The description fails to compensate for the missing parameter documentation.

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: 'Preview the effective cost of a tool call.' It specifies the verb (preview), resource (cost of a tool call), and adds distinguishing details about base cost and constraint effects. Among many schwab tools, this stands out as the pricing preview tool.

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 for checking cost before a tool call but does not explicitly state when to use it over alternatives (e.g., schwab_check_balance, schwab_check_payment). No exclusions or comparative guidance provided.

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