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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, and the description only restates 'Read-only' plus the HTTP endpoint. It does add a worthwhile safety caution about untrusted customer content, but that note reads as boilerplate for message-returning tools and is of unclear relevance to group metadata that contains no message text.

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?

Four short sentences, front-loaded with the action and scoped precisely; nothing is padding. The 'Read-only' sentence duplicates the annotations, which is the only wasted line.

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 read-only paginated list with no output schema, the agent still lacks the return shape (field names, whether counts/origins are per-group objects or scalars) and any indication of total-count or next-page behavior. Safety is covered by annotations, so the remaining gap is moderate rather than disqualifying.

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 0% for the two parameters, so the description must compensate and largely does not: 'a page of' implies limit/offset exist but gives no defaults, no explanation of the maximum of 100 or the offset range, and no ordering guarantee. The agent gets the concept of paging but none of the semantics the schema leaves undocumented.

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 ('Read a page of contact groups') and even names the notable return fields (counts, default origins), which is more than the title gives. It does not explicitly distinguish itself from the closest siblings get_group (single) or list_group_contacts (members of one group), though the plural 'groups' hints at the difference.

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?

'Read a page of' implies a paged listing, but there is no explicit guidance on when to use this versus smsglobal_get_group or smsglobal_list_group_contacts, and no stated prerequisites or pagination strategy. The agent must infer the routing decision from the tool names alone.

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