Get message statistics

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. Description adds value by specifying the exact statistics returned (overall totals and per-campaign breakdown) and listing possible errors (NO_ACTIVE_CUSTOMER/UNAUTHORIZED).

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, concise and front-loaded with action and result. Every sentence provides useful information without redundancy.

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?

Given no output schema, description sufficiently covers what the tool returns and error conditions. For a simple stats tool, it is complete enough, though a note on response format would enhance it.

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?

Tool has zero parameters, so schema_coverage is 100%. Per guidelines, baseline is 4. Description adds no parameter detail (none needed).

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?

Description clearly states the tool retrieves aggregate message counts (overall totals and per-campaign breakdown). The verb 'Get' and resource 'message counts' is specific, and it distinguishes from siblings like 'msg_send' (sending) and 'msg_list' (listing individual messages).

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 suggests use for 'a quick health check of messaging volume and delivery rates', providing clear context. Does not list alternatives or exclusions, but the purpose is well-defined.

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