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

Adds real context beyond the annotations: a 10,000-item per-request cap, duplicate records being silently skipped, the side effect of records becoming prospects, and that the call is free of credit charges. Annotations already declare idempotentHint=true and destructiveHint=false, so the description is not carrying the safety burden alone. It stops short of describing partial-failure behavior or what the response reports.

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, followed by limits and side effects. Every clause carries information an agent needs, and nothing is repeated or padded.

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 4-parameter mutation with full schema coverage and annotations, the description covers cost, limits, dedupe, and the prospect side effect. The remaining gap is the return shape (how many IDs were added vs skipped) on a partial failure, which matters for a batch mutation but is not covered anywhere since there is no 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?

Schema description coverage is 100%, so every parameter is already documented, including add_as_prospects and id_type. The description restates the add_as_prospects effect rather than adding new detail such as ID-scope rules per id_type. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ("Adds property or person IDs to an existing list"), and the phrase "existing list" implicitly separates it from dealmachine_list_create, while the prospect-filing sentence separates it from dealmachine_prospect_add. An agent can pick this tool without opening the schema.

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?

Usage is implied rather than stated: the tool works on lists that already exist and applies to property or person IDs. There is no explicit guidance on when to prefer dealmachine_prospect_add, what to do if list_id is unknown, or when to chunk requests under the 10,000-item cap. Adequate but leaves the alternative-selection reasoning to the agent.

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