list_groups

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: reads come from cache with no network call, implying possible staleness, and get_group forces a fresh update. Minor gap in not describing return shape or ordering.

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?

Two sentences plus three compact examples, with the cache/network constraint and the sibling routing front-loaded. Every element earns its place; the examples are short and directly actionable.

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 two-param read tool with full schema coverage and read-only annotations, the description covers the essentials plus the cache-vs-live distinction. No output schema exists and the description doesn't sketch the returned group fields, a small remaining gap.

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 both parameters are documented in the schema and baseline would be 3. The concrete examples ('{ query: "family" }', '{ limit: 10 }') demonstrate how the parameters compose in practice, adding practical meaning beyond the field descriptions.

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 all WhatsApp groups the user belongs to') and explicitly distinguishes itself from the sibling get_group by contrasting cache vs live reads. An agent can route between the two without opening either 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?

Gives explicit when-to-use context (cached, no network) and names the alternative tool with the condition that selects it (live snapshot of a single group via get_group forcing GroupMetadata.update). Nothing is left to inference.

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