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

Despite annotations marking readOnlyHint=false, the description explains why: it executes the path and rolls back every change, requires the anvil:write scope, and revalidates the revision. It also adds a security-relevant warning about untrusted CRM field values, which goes well beyond what the annotations convey.

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?

Three sentences, each earning its place: core behavior and return value, permission requirements, and a security warning. The most important distinguishing fact ('preview, never a completed action') is front-loaded. No filler or repetition of schema details.

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?

The tool is highly complex with 22 parameters, nested objects, no output schema, and almost no schema descriptions. The description covers purpose, side effects, and permissions well, but it leaves the agent without guidance on how to construct the required inputs or interpret the proposed state and effects. This is a significant gap for a tool this complex.

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 only 5% with 22 parameters, so the description carries the burden of explaining parameters. It does not explain any of the key parameters such as expectedUpdatedAt, expectedLifecycleRevision, idempotencyKey, finalTerms, correctedTerms, or how the action enum maps to different inputs. The phrase 'proposed lifecycle action' only hints at the action parameter.

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 states a specific verb ('Validates'), a clear resource ('proposed lifecycle action'), and the key behavior ('rolls back every change', 'Returns proposed state and effects'). It also explicitly distinguishes itself from actual lifecycle mutations by saying 'This is a preview, never authorization or a completed action', which separates it from siblings like close_record, transition_record_stage, and correct_closure.

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 gives clear context: use this to validate a proposed lifecycle action before committing, and it explicitly says it is not authorization or a completed action. It does not name specific sibling tools as alternatives, but the exclusion of 'completed action' strongly implies when to use it versus the actual mutation tools.

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