zms_list_app_zones

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

Annotations already declare readOnlyHint=true, so the description's 'Read-only' is redundant but not contradictory. Critically, it adds a prerequisite (ZSCALER_CUSTOMER_ID) and describes the output format (one row per app zone with fields), which goes beyond the annotation. This extra context about required environment and result shape is useful for safe invocation.

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 concise: two sentences that state the action, read-only nature, output fields, and a critical requirement. It is front-loaded and contains no fluff, making it quick for an agent to parse.

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 the tool is a simple list operation with a readOnlyHint annotation, the description provides sufficient context: output fields, read-only behavior, and a necessary environment variable. It doesn't explain pagination or sorting, but those are self-explanatory from parameter names and defaults. The lack of an output schema is offset by the description's clear field list. Overall, it is adequate for a straightforward listing tool.

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 only 20% (only the 'query' parameter has a detailed description). The tool description does not compensate by explaining any of the parameters (name, page_num, page_size, sort_order) or their roles. The user is left to infer that page_num and page_size control pagination, and name filters, but this is not stated. With low schema coverage, the description should add clarity but fails to do so.

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 the tool lists ZMS app zones and specifies the returned fields (id, name, description, resource count), which distinguishes it from sibling list tools. The verb 'List' and resource 'app zones' are specific, and it adds the requirement for ZSCALER_CUSTOMER_ID, further clarifying its scope.

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?

It provides basic usage context by stating it's read-only and requires ZSCALER_CUSTOMER_ID, but it does not explicitly mention when to use this tool versus alternative list tools or when not to use it. Given the many sibling tools, more explicit guidance on selection would be helpful, but the read-only and requirement hints offer some direction.

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