contact_add_labels

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

No annotations exist, so the description must cover behavioral traits. It only says 'Add Labels' with no info on whether it adds to existing labels or replaces, permissions needed, side effects, or error conditions. This is a severe gap for a mutation tool.

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 extremely short (2 words), but it under-specifies rather than being efficiently concise. It lacks structure and fails to convey essential information, so it does not earn 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?

Given the lack of output schema and annotations, the description should provide context about the tool's purpose, input constraints, and outcome. It only states 'Add Labels', which is incomplete for an agent to use it correctly without prior knowledge.

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?

With 100% schema coverage, the schema already describes the 'labels' parameter as an array of comma-separated strings. The description adds no further meaning beyond what's in the schema, so a baseline of 3 is appropriate.

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 'Add Labels' is minimal but states a verb and resource. However, it lacks specificity about the target (contact) and could apply to other entities, though the tool name clarifies it's for contacts. It's barely above a tautology.

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 usage guidance or alternatives are provided. There are sibling tools like 'list_all_labels_of_a_contact' and 'conversation_add_labels' that could be confused, but the description offers no help in differentiating when to use this tool.

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