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

The annotations already provide the read-only safety profile (readOnlyHint=true) and workspace scoping (openWorldHint=false). The description adds behavioral context beyond that: newest-first ordering and the specific progress data included (requested, added, skipped, email verification, credits spent), which helps the agent set expectations without contradicting the annotations.

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?

A single well-structured sentence that front-loads the core action and resource, then efficiently lists the return fields. No filler or redundancy; every clause adds information.

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 simple read-only list tool with one optional parameter and no output schema, the description is quite complete: it conveys scope, ordering, and the fields returned. It doesn't describe pagination or total counts, but that is a minor gap given the tool's simplicity and the read-only annotation.

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 100% because the only parameter (limit) is fully documented with type, bounds, and default. The description does not mention the limit parameter or add any semantics beyond what the schema already provides, so the 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 uses a specific verb ('Lists') and a clear resource ('workspace's Lead Finder adds'), then disambiguates what that means ('people added to campaigns from the contact database'). It also states ordering ('newest first') and enumerates the returned data fields, making it unmistakable from siblings like list_leads or get_lead_finder_import.

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 scoping ('workspace's') and the detailed field list imply when this tool is useful, but there is no explicit guidance on when to use it versus alternatives like get_lead_finder_import (singular) or search_lead_finder. No exclusions or alternative conditions are stated, so the guidance is implied rather than explicit.

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