list_lead_lists

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

Annotations carry readOnly, idempotent, and non-destructive hints. The description adds useful context: requires API key and connected account, empty result means no lists exist yet, and explicitly notes it costs no credits. Minor deduction for describing the read-only nature, which was redundant with the annotation.

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?

Front-loaded with the core one-line definition, followed by scannable guidance on when to use it, with references to sibling tools and prerequisites. Every sentence contributes, including the empty-result edge case. Well-scoped for a zero-parameter tool.

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 parameterless, side-effect-free list tool with strong annotations and no output schema, this description covers what an agent needs: purpose, when to use it (avoid duplicate lists), prerequisites (API key, connected account), behavior on empty results, and cost implications. No unnecessary output format explanation is needed given the absence of an output schema.

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?

Zero-parameter tool, so baseline is 4 per the rubric. The description confirms this with 'takes no parameters' rather than remaining silent. No schema deductions needed for a parameterless and succinct tool.

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?

Clear verb+resource in sentence one: "List the Hunter.io lead lists connected to this account." Distinguishes itself from sibling tools by naming search_leads, create_lead_list, sync_lead_list, and list_leads explicitly, referencing their alternatives.

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?

Explicit when-to-use guidance: use to find listId pre-sync, or to check for duplicates pre-create. Differentiation from siblings is explicit: "these are Hunter.io's lists, which are separate from the leads stored locally — list_leads shows those."

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