dex_update_contact

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

With no annotations provided, the description carries full burden. It discloses the partial update behavior ('Only included fields are modified; omitted fields remain unchanged'), which is valuable. However, it doesn't mention authentication requirements, rate limits, error conditions, or what happens on success/failure. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 appropriately front-loaded with the core purpose and partial update behavior. However, the exhaustive field listing creates redundancy with the schema and could be more concise. Some sentences (like the field enumeration) could be trimmed while maintaining clarity.

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 a mutation tool with 2 parameters, complex nested objects, no annotations, and no output schema, the description does well on parameter semantics but lacks behavioral context. It explains what can be updated but not how the update behaves (e.g., validation, error responses). For this complexity level, it's partially complete but has notable gaps.

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 must compensate. It provides extensive semantic context beyond the schema: explains the partial update mechanism, lists all supported fields with examples of complex structures (emails array, tags with append/remove operations), and clarifies that 'data' contains the updatable fields. This adds substantial value over the bare schema.

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 the verb 'Update' and resource 'contact by ID', making the purpose explicit. It distinguishes from siblings like dex_create_contact (create) and dex_delete_contact (delete), but doesn't explicitly differentiate from other update tools like dex_update_group or dex_update_tag.

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?

No guidance on when to use this tool versus alternatives is provided. The description doesn't mention prerequisites (e.g., needing a valid contact ID), when to choose this over dex_merge_contacts, or when to use sibling tools like dex_manage_contact_tags for tag operations instead. Usage is implied but not explicitly stated.

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