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

Annotations already declare that this is a destructive, idempotent, open-world write. The description adds important behavior beyond annotations: it is a PATCH-style partial update where only supplied fields change, and it lists fields this tool does not touch. It does not explain overwrite semantics for the nested emergency_contact object or auth/error behavior, but the core mutation behavior is disclosed.

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 compact sentences with the write intent, field scope, exclusions, and endpoint all front-loaded. Every sentence adds useful information without repetition.

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?

For a 10-parameter destructive write with no output schema, the description covers the essential scope: it identifies the updatable fields, partial-update behavior, and excluded areas. It could be more complete by explaining emergency-contact replacement semantics and what the response contains, but it is sufficient for correct invocation.

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 30%, so the description must compensate. It does list the main updatable fields—names, date of birth, gender, employee number, title, and emergency contact—and clarifies that only passed fields change, but it does not add detail for enum values, date format, or emergency-contact subfields beyond what the schema itself provides.

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: 'WRITE: change fields on an existing person,' then enumerates the updatable fields and explicitly excludes contact details, addresses, and jobs. This clearly distinguishes it from create/get/list sibling tools and even names the underlying endpoint.

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 clearly defines when to use the tool—updating the listed fields on an existing person—and when not to use it by excluding contact details, addresses, and jobs. It does not name the sibling tools to use for those excluded operations, so it stops short of full alternative routing.

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