Update contact

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

Annotations declare readOnlyHint=false, openWorldHint=true, and idempotentHint=true, but the description adds the key behavioral detail that only provided fields are changed, i.e., a partial update rather than a full replacement. This is valuable context beyond the annotations. It does not contradict any annotation and clarifies a core side-effect.

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 a single, efficient sentence that front-loads the purpose and includes the critical behavioral constraint. There is no redundant or filler content; every word earns its place.

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?

The tool is a mutation with 7 parameters and no output schema. The description covers the essential purpose and partial-update behavior, and annotations provide safety and idempotency hints. However, it omits details like error handling (e.g., what happens if the contact doesn't exist) and any restrictions on specific fields, which would be helpful for an agent but are not critical for basic 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 29% (2 of 7 properties have descriptions). The tool description adds nothing specific about parameter meanings or formats—it only states a general partial-update rule. For a tool with low schema coverage, the description should compensate, but it does not, leaving semantic gaps for fields like email, phone, and names.

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 clear verb and resource: 'Update fields on an existing contact.' It distinguishes from create (which implies a new record) and from read/delete operations. The phrase 'existing contact' and 'Only provided fields are changed' adds specific semantics that separate it from full replace operations.

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 implies usage for modifying an existing contact and that only supplied fields are changed, which is a partial-update guideline. However, it does not explicitly mention alternatives like ghl_create_contact for new records or ghl_add_contact_tags for tag-specific behavior, nor does it exclude them in certain contexts. The guidance is present but not fully explicit.

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