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 only states the basic action of creating a contact, but omits critical behavioral details like whether duplicate email addresses are rejected, whether the operation is idempotent, any authentication requirements, or what the response contains. This leaves significant behavioral ambiguity.

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, concise sentence that immediately states the tool's purpose. It is efficiently front-loaded and free of unnecessary words, though it could be slightly expanded without losing conciseness.

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 lack of an output schema and annotations, the description is insufficiently complete. It does not mention return values, error handling, duplicate detection, or other behaviors essential for an agent to anticipate the tool's effects. The brief description leaves many operational questions unanswered.

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?

The input schema has 0% parameter description coverage, and the description fails to compensate by elaborating on any of the five parameters (email, phone, firstName, lastName, tags). While the parameter names are somewhat self-explanatory, the description adds no context about formats, constraints, or how parameters relate to the creation process.

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 'Create a new CRM contact' uses a specific verb ('create') and resource ('contact'), clearly distinguishing it from sibling tools like update_contact, get_contact, and search_contacts. It leaves no ambiguity about the tool's primary function.

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 no guidance on when to use this tool versus alternatives, such as updating existing contacts (update_contact) or searching for contacts (search_contacts). It also does not mention any prerequisites or contexts where this tool is the appropriate choice.

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