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

Annotations declare non-read-only, non-idempotent, non-destructive, but the description adds substantive context beyond them: the two-party signing requirement, the prohibition on the broker signing, and the mandatory ends_at (no perpetual contracts). It does not discuss reversibility or auth/rate constraints, but the added lifecycle context is genuinely useful.

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, front-loaded with what the tool does, then the critical binding caveat and the ends_at constraint. No filler or repetition of the title.

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 10-parameter nested-object tool with no output schema, the description covers the essential lifecycle and the mandatory constraint. It leaves return/result behavior unstated, but annotations carry the safety profile and the schema carries parameter detail.

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 100%, so the baseline is 3. The description reinforces that ends_at is required and forbids perpetual contracts, but adds little syntax or semantics for the remaining nine parameters beyond what the schema already documents (including the nested terms object).

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 (draft/propose) and resource (bilateral, term-bound contract between company and agent), and makes scope explicit ('either sovereign party may propose'). It clearly distinguishes itself from the sibling sign_contract by noting the proposal is NOT binding until signing.

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?

Gives clear context: use this to draft/propose, and the binding action is deferred to sign_contract with an explicit warning that the broker never signs on either's behalf. It does not enumerate when-not-to-use or other alternatives (e.g. amend_plan, terminate_contract), so it stops short of full routing guidance.

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