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

Annotations only say write-ish but non-destructive; the description adds real behavioral weight: the tool creates open items and hard-gates the close ('the close can't be signed until every one is received, mapped and certified'). It omits idempotency (what happens on a re-run when a list already exists) and the error mode when the agreement has no matching rule.

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?

Front-loaded with the action and scope; the mid-sentence examples (sell-side rebate → POS extract) earn their space by showing the derivation logic. The stacked parentheticals make it denser than it needs to be, but there is no filler.

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?

With no output schema and only minimal annotations, the description carries the burden well: it covers the source of truth (the agreement), the downstream consequence (open items gating sign-off), and the precondition. Return shape and duplicate-handling behavior are the remaining gaps, which matter less for a one-parameter drafting call.

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% for the single engagement_id, so the schema already does the documentation work. The description adds only the implicit precondition that the referenced engagement must carry an active agreement, which is useful but thin — baseline 3 applies.

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 + resource: 'Draft the PBC (prepared-by-client) document list for an engagement, FROM its agreement.' The parenthetical expansion and the derivation-from-agreement clause make the purpose unambiguous. It doesn't explicitly name a sibling it is not (e.g., receive_document, open_items), so it falls just short of a 5.

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 a clear precondition ('Needs an active agreement first') and a usage signal that it is derived, not generic ('never a generic ask'). It does not state when to use an alternative such as receive_document for already-collected files, nor what to do when a list already exists.

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