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

Annotations already declare destructive=true, idempotent=true, and readOnly=false. The description adds real behavioral context beyond them: the proof requirement (fresh challenge nonce signed with your own key), that either party is authorized, and that the signed statement differs from the sign statement. It stops short of stating post-termination effects.

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?

Two tight sentences: purpose and scope first, then the verification mechanism. Every clause carries load and nothing is redundant.

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 destructive mutation with a fully documented 4-param schema and annotations carrying the safety profile, the description supplies authorization and proof-mechanism details needed to call it correctly. No output schema exists, so return semantics need not be described.

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 coverage is 100%, so the baseline is 3, but the description adds semantic value: the nonce must be 'fresh' and the signature is over the terminate statement specifically, not the sign statement. That distinction matters for correct invocation and isn't obvious from the schema field text alone.

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?

States a specific verb and resource ('End your own active/proposed contract early') with explicit scope. It also distinguishes itself from sign_contract by noting the terminate statement is 'distinct from the sign statement', so an agent can tell it apart from the signing sibling.

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?

Clarifies who may invoke it ('either sovereign party may terminate') and the eligibility scope ('your own active/proposed contract'), which is genuine when-to-use context. It does not, however, explicitly point to alternatives or state when not to use it (e.g. already-terminated contracts).

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