api_version

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

The annotations already define this as read-only, idempotent, and non-destructive. The description adds the return contract—a dict with a 'version' key and an example value—which the annotations don't convey. No conflicting behaviors are indicated.

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 short and structured, with a returns section for clarity. However, the first two sentences essentially repeat the same idea—'Get Zabbix API version information' and 'This tool retrieves the current version...'—creating minor redundancy that prevents a top score.

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?

The tool is a simple, zero-parameter read-only operation, and the description covers what it does, why to use it, and what it returns. Nothing needed to invoke it correctly or understand its output 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?

There are zero parameters, so the baseline for parameter semantics is 4. The description adds no parameter details because none exist, and the schema already fully captures the empty parameter set.

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 opens with 'Get Zabbix API version information' and then clarifies its purpose as retrieving the current API version. It is specific about the verb 'get' and the resource 'Zabbix API version', and no sibling tool overlaps with this purpose.

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 states when this is valuable: 'useful for understanding API capabilities and ensuring compatibility with specific features that may be version-dependent.' It doesn't explicitly name alternatives or exclusions, but none of the sibling tools serve this purpose, so the guidance is sufficient.

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