cdr_count_by_code

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It mentions the tool is cheap (low cost), which is useful. But it does not state whether it is read-only, any required permissions, or other side effects. The presence of an output schema reduces the need to describe return values, but other behavioral aspects are missing.

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?

The description is extremely concise: two short sentences. The first states the core function, and the second adds context and value. No redundant or unnecessary words.

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 aggregation tool with two parameters and an output schema, the description covers the purpose, use case, and performance characteristic adequately. It does not explain the output format, but that is handled by the output schema. Slight lack of guidance on parameter details prevents a perfect score.

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%, so the description should compensate by explaining parameters. The description mentions 'within a window' which loosely relates to date_from and date_to, but it does not describe the format, constraints, or how they are used. Most of the parameter meaning must be inferred from names alone.

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?

The description clearly states it counts CDRs by SIP response code within a date window, and gives a concrete use case ('what's the 5xx rate right now?'). It distinguishes itself from siblings only implicitly by mentioning 'SQL-side aggregation' and being cheap, but does not explicitly differentiate from related tools like cdr_summary or cdr_audit.

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?

The description suggests using it for a quick-glance aggregate report, implying a lightweight use case. However, it provides no explicit guidance on when not to use it or what alternatives (e.g., cdr_summary, acc_query_cdrs) are better suited for other scenarios.

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