Update Contact

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

The annotations already mark the tool as destructive (destructiveHint=true), so the description does not need to restate that. It adds a useful note about the return value ('compact summary with the contact slug') and the 'at least one field' requirement, but does not elaborate on side effects, overwrite semantics, or error cases, which is acceptable given the annotations.

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?

Three focused sentences: the first states the core action, the second gives the required-parameter rule and resolution sources, and the third describes the return value. Every sentence adds value, and the most important information is front-loaded.

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 22 parameters, an output schema, and annotations, the description covers the essential usage constraints and foreign-key resolution strategies. It does not enumerate all possible fields, but the schema already does that. The only minor gap is not mentioning what happens if no update field is provided beyond the requirement itself, but that is adequately communicated.

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 schema covers all 22 parameters (100% coverage), so the baseline is 3. The description adds meaningful semantics by clarifying that at least one update field is required and by explaining how to resolve foreign keys (user IDs via list_users, company slugs via search_companies/list_companies, stage IDs via list_contact_stages, custom field IDs via list_custom_fields). This goes beyond the schema's per-field descriptions.

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 opens with a specific verb ('Updates') and precisely identifies the resource ('one existing Recruit CRM contact') and the addressing mechanism ('by contact_slug'). This clearly distinguishes it from sibling tools like create_contact, list_contacts, search_contacts, and get_contact_details.

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 clearly states the required inputs ('Requires contact_slug and at least one field to update') and provides explicit pointers to related tools for resolving user IDs, company slugs, stage IDs, and custom field IDs. It does not explicitly state when not to use this tool, but the 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.