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

Annotations already mark this as a non-read-only, non-idempotent mutation, and the description adds that it creates a new static list and can optionally add leads. However, it does not disclose uniqueness, response shape, or failure behavior, though the annotations lower the bar.

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 sentences, action-first, with no filler. Each sentence adds distinct value: the core action, optional lead addition, and prerequisite ID lookups.

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 description is complete enough for selecting and invoking the tool: it covers the required campaign scope, optional leadRefs, and ID sourcing. It could mention the response/return value or point to add_leads_to_list for existing lists, but these are not blockers.

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 0% schema description coverage, the description compensates by explaining leadRefs structure (leadSource default 'global' and leadId) and how to obtain campaign and lead IDs. It slightly overstates leadSource as 'needs' when the schema makes it optional with a default, so it is not perfect.

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 specific action and resource: 'Create a new static lead list in a campaign.' The word 'static' also distinguishes it from the sibling campaignstack_create_query_lead_list, so the agent can identify the correct tool immediately.

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?

It provides clear context for when to use the tool (creating a new static list) and gives concrete lookup guidance: use campaignstack_list_campaigns for valid campaign IDs and campaignstack_search_leads for lead IDs. It does not explicitly contrast with add_leads_to_list or create_query_lead_list, but 'new' and 'static' make the primary use condition clear.

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