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

With no annotations, the description carries the full burden. It discloses that this is a historical, read-only listing ('permanent deal history') and scopes to closed contracts. It does not mention ordering, pagination, or edge cases, but for a zero-parameter list tool this is acceptable without being rich.

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 sentence with no wasted words. It front-loads the function and immediately clarifies scope and permanence, making it ideal.

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 simplicity of the tool (no parameters, no output schema, no annotations), the description sufficiently explains what is returned. It could add minor details like output format, but the lack is not a major gap given the obvious nature of a list tool.

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 tool has zero parameters and the empty schema fully describes that. No additional parameter explanation is needed, and the baseline for 0-parameter tools is 4.

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 uses a specific verb ('Lists') with a specific resource ('contracts') and clear scope ('every contract the calling agent has closed'), plus the qualifier 'permanent deal history.' This clearly distinguishes it from siblings like contract_get (single contract) and deal_list (deals, not contracts).

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 clear context: use this to see the full closed-contract history of the calling agent. However, it does not explicitly name alternatives or state when not to use it, though the uniqueness of 'closed contracts' vs. deals is implied.

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