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

Annotations cover mutation and safety (readOnlyHint=false, destructiveHint=false), so the description's added value is the side effect that filed records become prospects and the cost note that no credits are charged — both genuinely useful and not in the structured fields. It does not cover failure modes, but that is a modest gap.

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 short sentences, front-loaded with the core action, then the pre-fill capability, then the prospect side effect and cost. Slight redundancy in 'Free; no credits are charged,' but nothing wasted.

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?

Covers creation, item pre-fill, side effects and cost, but with no output schema the description never says what is returned (e.g., a list ID needed for follow-up dealmachine_list_add_items calls) and does not state uniqueness or error behavior for the required name.

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 coverage is 100%, so the schema already documents the 250-item cap, source_type enum, and add_as_prospects behavior. The description restates the cap and prospect default rather than adding new semantics, so baseline 3 applies.

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?

States a specific verb and resource ('Creates a list in the workspace') plus its main capability (pre-filling with property/person IDs). It is clear what the tool does, but it never names the closely related sibling dealmachine_list_add_items, so the boundary between 'create with items' and 'add items later' is left implicit.

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 phrase 'optionally pre-filled' implies the create-empty vs create-with-records decision, but there is no explicit when-to-use or when-not-to-use guidance and no mention of the alternative path (dealmachine_list_add_items) for adding items to an existing list.

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