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

The readOnlyHint annotation is consistent with the description and indicates no side effects. The description adds useful behavioral details such as response body truncation to 'first 4 KB' and redaction of 'credential headers,' though it does not mention possible error conditions like a missing event ID.

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?

The description is a single, compact sentence that conveys the resource, the returned details, the truncation/redaction behavior, and the prerequisite. No unnecessary words or redundant information are present.

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?

Since there is no output schema, the description sufficiently explains what the caller will receive: per-field deviations, the arrived value, route, request, and response body, along with truncation and redaction notes. It also mentions the required project context and the source of event IDs, making it complete for invoking the tool.

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?

Both parameters are described in the schema, with projectId defaulting to session context and driftEventId being the required event identifier. The description adds extra context that event IDs come from list_contract_drift and that project context is required, which goes slightly beyond the schema descriptions.

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 clearly identifies the tool's purpose: retrieving one contract drift event with detailed per-field deviations, the actual arrived value, route, request, and response body. It distinguishes this from the sibling list_contract_drift by explicitly stating 'Ids come from list_contract_drift' and focusing on a single event 'in full.'

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 provides key usage guidance by stating that IDs come from list_contract_drift and that project context is required. It does not explicitly contrast with all related tools, but the phrase 'One contract drift event in full' and the ID source make the intended use case clear.

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