Update ServiceNow record

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

Annotations already declare readOnlyHint=false and destructiveHint=false, indicating a mutating but non-destructive operation. The description adds no additional behavioral context, such as permissions, reversibility, or the preview/plan mode behavior encoded in the 'apply' parameter. It is consistent with annotations but adds little beyond them.

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, front-loaded sentence with no redundant words. It immediately names the action, target, and key identifier, making it efficient and easy to parse.

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?

Given the rich schema (which covers parameters and the apply/preview behavior) and the annotations covering mutation safety, the concise description is sufficient for an agent to understand the tool's core purpose. It does not explain the preview mode, but that is fully documented in the apply parameter description, so nothing critical is missing.

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 schema fully documents all five parameters, including table, sys_id, fields, and the apply flag. The description itself adds no parameter-level meaning, so a baseline score of 3 is appropriate.

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 ('Update'), a resource ('fields on an existing record'), and the identifier ('sys_id'). This clearly distinguishes it from creating, deleting, querying, or fetching records, so an agent can select it without ambiguity.

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 implies the tool is for modifying existing records (as opposed to creating or deleting), but it does not explicitly mention alternatives or state when not to use it. No prerequisites or exclusions are given, so the guidance is adequate but not explicit.

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