create_custom_field

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

With no annotations, the description must reveal behavior. It only states it creates a field and adds data storage context, but omits side effects (e.g., duplicate handling, required permission levels, or impact on existing records).

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?

Two sentences with no redundancy. The first sentence states the action, the second provides context. Could be slightly more informative without sacrificing conciseness, but no wasted words.

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 tool with 4 parameters, 2 enums, and no output schema, the description is incomplete. It misses explaining the relationship between picklist_values and field_type, and does not cover error conditions or success responses.

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 coverage is 100%, so the description does not need to explain parameters individually. The description adds a general use case but does not clarify the dependency between picklist_values and field_type or entity_type with 'opportunity'. 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?

Description explicitly states it creates custom fields for contacts or accounts, and the input schema adds 'opportunity'. The action is clear, but the omission of 'opportunity' in the description slightly reduces precision.

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?

No guidance on when to use this tool versus others, or any prerequisites like admin permissions. The word 'FREE' hints at cost but does not inform usage context.

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