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

Annotations already indicate a write operation (readOnlyHint=false). The description adds 'Requires write scope,' which is useful authentication context. It does not disclose other behaviors such as error cases or idempotency, but these are partially covered by annotations (idempotentHint=false). No contradictions found.

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 extremely concise — two short phrases that convey the core purpose and a key requirement. Every word earns its place, with no redundancy or filler.

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 simple tool complexity, complete schema coverage, and available annotations, the description is mostly sufficient. It lacks mention of return values (no output schema), but this is a minor gap for a straightforward create operation. The write scope note adds useful context.

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%, so all parameters (email, phone, lastName, firstName) are already documented in the schema. The description adds no additional parameter-level meaning, matching the baseline of 3 for high coverage.

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 'Create a new contact' with a specific verb and resource, distinguishing it from sibling tools like update_contact and delete_contact. The purpose is immediately obvious.

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. It does not mention that this is for new contacts only, nor does it reference update_contact for existing contacts. The only hint is 'Requires write scope,' which is a permission note, not usage guidance.

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