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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation risk is known. The description adds some behavioral context by naming archiving as a possible operation, but it does not explain what archiving implies or what else may be affected.

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?

A single sentence delivers the full behavioral intent without any filler. Every phrase corresponds to a meaningful parameter or usage scenario.

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 output schema exists, annotations cover the destructive nature, and the description explains all three mutable fields, the definition is largely complete. It lacks explicit guidance about when not to use it, but that is a minor gap for this simple tool.

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 0%, so the description carries the burden of explaining parameter intent. It successfully maps 'rename' to name, 'set their contact' to contact, and 'archive' to archived, adding meaning beyond the raw schema. It does not add detail for id, but the schema already marks it as required and self-explanatory.

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 names the specific resource (a person you split with) and the concrete operations: rename, set contact, or archive. This clearly distinguishes update_person from the many sibling update_* 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 phrase 'someone you split with' provides clear context for when to use this tool, and the listed actions (rename, set contact, archive) define its intended scope. It does not explicitly mention alternatives or exclusions, but the usage context is clear enough.

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