Explain Field

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful details about the output content (type, constraints, help text, choice values), but it does not disclose any additional behavioral traits such as failure modes, permission requirements, or whether fields without choices are omitted. With annotations present, this is adequate but not exceptional.

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 two sentences: the first states the exact purpose and output contents, the second gives a clear usage directive. It is front-loaded, no filler, and every sentence earns its place.

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?

For a read-only explanation tool with no output schema, the description covers the main intent, output expectations, and a usage cue. It does not mention error scenarios (e.g., field not found) or distinguish from similar field-related tools, but it is largely complete for its simplicity. A 4 is appropriate.

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% — every parameter (table, field, instance) has a meaningful description. The tool description itself does not add parameter-specific details beyond what the schema provides, so the baseline of 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?

The description uses a specific verb ('Get detailed explanation') and resource ('a specific field on a ServiceNow table'), and enumerates what the explanation includes (type, constraints, help text, choice values). This makes it clearly distinct from sibling table-level tools like 'discover_table_schema' or 'lookup_columns'.

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 a clear usage context: 'Use this to understand what a field does... before reading or writing data.' This tells the agent when to use it, though it does not explicitly name alternative tools or state when not to use it, so it falls short of a 5.

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