List contact groups

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

Annotations already declare readOnly/idempotent/no-destructive, so the description correctly spends its words elsewhere: it discloses the billing consequence of group sends ("every member is charged"), which is real behavioral context the annotations cannot express. It omits pagination/return-shape detail, but an output schema exists to cover that.

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, both front-loaded: what it returns first, then the actionable cost warning. No filler and no restatement of the title.

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?

A read-only paginated list tool with full param coverage and an output schema needs only purpose plus the non-obvious hazard — the per-member charge — and both are present. Nothing an agent needs to call it safely is missing.

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% (limit and cursor are both documented, including the next_cursor paging idiom), so the schema carries parameter meaning. The description adds nothing about the parameters themselves — 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 ("List the contact groups in SendKuy") plus the enrichment it returns ("how many contacts each holds"), which distinguishes it from contact-level siblings like sendkuy_find_contacts. It does not, however, explicitly name a sibling it should not be confused with.

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 concrete downstream guidance: put the grp_... id in the `to` field of sendkuy_send_message, and check contact_count first because every member is charged. That covers when to use the output, but there is no exclusion guidance (e.g. when to use find_contacts instead).

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