dnc_add_entry

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

With no annotations, the description carries the full burden and discloses the key side effect: 'all subsequent outbound calls (manual or campaign) to this number from your org will be blocked at dial time.' It also mentions the optional reason. However, it doesn't address idempotency or reversibility (via dnc_delete_entry).

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 succinct and front-loaded, with only 3 sentences and a clear Args block. Every sentence adds value, and the structure makes it easy to scan.

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 covers the main functionality and side effect, and output schema likely exists on the tool, so return values don't need explanation. It misses minor edge cases like duplicate additions or how to remove the entry, but overall it's sufficient for a simple add tool.

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%, but the description fully compensates by documenting both parameters: phone as 'E.164 formatted number' and reason as 'Optional human-readable reason' with examples. This adds format, optionality, and examples beyond 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 'Add a number to your organization's DNC list' with a specific verb and resource. It also explains the consequence (blocking outbound calls), which distinguishes it from siblings like dnc_check or dnc_delete_entry.

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 use when you need to prevent outbound calls to a number, but it doesn't explicitly name alternatives or when-not-to-use. It gives clear context about the effect, which is enough for most agents to select it appropriately.

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