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

Adds real context beyond the annotations: refuses when no engagement is open and routes back to open_engagement, requires a connected Aurgus account, and clarifies that nothing posts to the GL. Two gaps remain: readOnlyHint=false is not explained (presumably the computed result is persisted inside the engagement), and there is no statement about re-running (idempotency / whether a second call overwrites the prior computed close).

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 core identity ('The RUN step (step 6)…') followed by the anti-pattern warning, prerequisites, return content, and side-effect note in a logical order. It is on the long side for a zero-parameter tool, but each sentence carries distinct information.

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, the description usefully previews the return ('the number, how earned / claimed / credited line up, and any flag worth raising'). Combined with prerequisites, refusal behavior, GL non-posting, and the auth requirement, an agent has everything needed to call it correctly and interpret the result.

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 takes zero parameters and the schema coverage is 100%, so nothing needs documenting. The description correctly implies the tool derives its input implicitly from the open engagement state rather than from arguments.

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 — 'The RUN step (step 6) of an open engagement' that works the earned → settled → open accrual across active agreements and certified data. The domain scoping ('earned → settled → open accrual', 'active agreements', 'certified data') clearly separates it from siblings like compute_commission, compute_lease, compute_trade_spend, and recalculate.

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?

Explicitly names the wrong first move ('Do NOT call this as the first thing when a user says compute the close'), enumerates the required prerequisite chain (open_engagement → establish agreement → request + certify data → run), and states the fallback behavior when no engagement is open. The alternative (open_engagement) and the condition selecting it are both given.

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