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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the bar is lower, yet the description still adds substantive behavior: a two-step preview/confirm flow and duplicate-detection semantics. It omits auth/permission requirements and rate limits, but the preview mechanic is a meaningful disclosure beyond the annotations.

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?

Three sentences, front-loaded with the create action, then the workflow caveat. Every sentence carries a distinct piece of information with no 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?

With no output schema, the description usefully explains what the preview returns (a possible existing match), covering the main unknown an agent would face. It does not enumerate the remaining input fields, but for a 14-param create tool with mostly obvious field names, this is close to sufficient.

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 only 21%, so the description must compensate. It does explain the trickiest params — email/phone requirement, the confirm sequencing, and create_duplicate's conditional use — but leaves the address/name/tags fields undocumented, which is acceptable only because their names are self-evident.

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 and resource ('Create a new prospect (contact) in a HighLevel sub-account'), which is clearly distinct from the read-oriented sibling highlevel_find_contact. It is clear on what the tool does, but never names the sibling it complements, so differentiation is inferred from the duplicate-check narrative rather than stated.

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?

It gives explicit sequencing ('Call without confirm first') and a decision rule for the returned match ('use that contact instead unless the human tells you it is genuinely a different person'). This tells the agent both when to call and what to do with the result, leaving little to inference.

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