Update Contact Person

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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is largely covered, but the description adds nothing about what is actually destroyed or mutated. For a destructive update, the critical question of whether omitted body fields are cleared or preserved is left entirely unstated, and the duplicate-email behavior lives only in the nested schema, not the description.

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 text is short, but the first line "Update Contact Person" merely restates the title and consumes space before the informative sentence. The remaining two sentences are efficient but the front-loading wastes the strongest position on a tautology.

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?

This is a destructive, open-world mutation with a nested body object and no output schema, so the description carries real burden. It says nothing about what a successful response contains, required permissions, whether unlisted fields are reset, or how custom property keys interact with the standard fields beyond a pointer to the schema.

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%, and the nested body schema already documents the email duplicate-check mode and the custom-property convention via propertyIdentifier and list_properties. The description contributes only the constraint that the body should contain contact-person fields, which is marginal added meaning over the schema; the baseline 3 applies.

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 a specific verb and resource ("Updates an existing contact person by ID") and adds a scope constraint ("only accepts contact person fields"), which hints at why this exists alongside update_contact. It never names create_contact_person, delete_contact_person, or update_contact explicitly, so sibling differentiation is implied 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?

"Updates an existing contact person by ID" implies the precondition that the record must already exist, and "only accepts contact person fields" implicitly steers callers away from sending parent-contact fields. There is no explicit when-to-use/when-not-to-use guidance, no mention of create_contact_person for new records, and no statement about whether this is a partial or full replacement.

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