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

No annotations are provided, so the description must disclose behavioral traits. It only mentions the bulk nature and 100-item limit, but omits critical information such as authentication requirements, idempotency, duplicate handling, or failure behavior. For a write operation, this is insufficient.

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, front-loaded sentence 'Bulk add contacts (max 100)' with no wasted words. It delivers the essential scope and limit efficiently.

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?

For a bulk operation with nested object fields, no output schema, and no annotations, the description is too sparse. It does not explain how to format contacts, what happens if the limit is exceeded, or what the response contains. This leaves critical gaps for an agent attempting to invoke the tool correctly.

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%, and the description adds no explanation of the 'contacts' parameter structure or field meanings beyond what the schema property names already show. The description fails to compensate for the lack of schema descriptions, leaving the agent to infer semantics from names like 'title' and 'company'.

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 'Bulk add contacts (max 100)' clearly specifies the action (add) and resource (contacts). It distinguishes itself from the sibling 'add_contact' by explicitly indicating a bulk operation, making the purpose unambiguous.

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 adding multiple contacts with a maximum batch size of 100. However, it does not explicitly state when to prefer this tool over 'add_contact' or mention any exclusions or alternative tools. Still, the bulk context provides clear usage direction.

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