reach_createAContactFieldV1

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the slug is derived from the label and that both slug and type cannot be changed later, which are significant non-reversibility details. It also notes the returned uuid for setting values, giving workflow context.

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, front-loaded, and each sentence earns its place. The first states the purpose, the second provides critical lifecycle details. No filler or redundancy.

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 description covers the core workflow: define field, receive uuid, set values on contacts. It also warns about immutability. With the schema documenting option requirements, this is sufficient, though it lacks explicit guidance on when not to use and edge cases like label uniqueness.

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 baseline is 3. The description adds meaning by explaining that label derives the slug and that type is immutable, which are not captured in the schema descriptions (which are mostly tautological like 'label parameter'). This adds value beyond the schema.

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 states the tool defines a new custom contact field in a profile. It uses a specific verb ('Define a new') and identifies the resource ('custom contact field') and scope ('in a profile'). This distinguishes it from sibling update/delete/list field tools.

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 use case (creating a new field) and instructs the user to use the returned uuid for setting values on contacts. However, it does not explicitly mention alternatives like updating or deleting fields, nor does it state when not to use this tool. The context is clear but lacks exclusions.

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