lead_groups_read

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

Annotations already declare readOnly/idempotent/openWorld, so the safety profile is covered; the description adds real value beyond that by explaining the tags filter is OR-semantics ('only counts leads carrying at least one of the tags') and that counts are per-group. It does not mention pagination, ordering, or the mode parameter's effect on response size beyond what the schema says.

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 what is returned, then the filter rule, then the alternative tool. No filler or repeated boilerplate.

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?

With no output schema, the description does the necessary work of saying the result is groups with lead counts, and the filter semantics are covered. Missing only secondary detail such as ordering or whether empty groups are included, which an agent may want before calling.

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 only 33%, so the description must compensate; it does for tags by spelling out the 'at least one' matching rule, and agentId's role is clear from the first sentence. The mode parameter is left entirely to the schema, but that schema entry is self-documenting, so the gap is minor.

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 ('List the lead groups of an agent') plus the payload ('with the number of leads in each'), which lets an agent distinguish it from sibling leads_read (individual leads) and lead_groups_write. The parenthetical tying groups to campaign.leadGroupName anchors the concept in the domain model.

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?

Explicitly routes the drill-down case: 'To see the leads inside a group use leads_read with groupName.' That names both the alternative and the parameter to use. It does not state exclusions relative to other listing tools (e.g., campaigns_read) but the guidance present is concrete.

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