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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered for this zero-argument read. The description adds the sequencing constraint but nothing about what the returned schema looks like or when it might change; with an output schema present, that omission is minor, so a 3 is fair.

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, no filler. The 'what' comes first and the 'when' second, which is the right front-loading for a prerequisite fetch tool.

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?

With an output schema present, return values need no explanation, and the zero-parameter input eliminates ambiguity. What remains unclear is whether the same schema applies to update_api_template, a small but real gap for a tool whose entire job is to be consulted before authoring.

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?

The tool takes no parameters and the input schema is an empty closed object, so there is nothing to disambiguate. Baseline 4 applies.

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?

Specific verb plus resource: it returns the JSON Schema that an API template definition must satisfy. That makes it immediately distinguishable from get_api_template / list_api_templates, and the named consumers (create_api_template / create_api_template_version) anchor its role in the family of sibling definition-schema tools.

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 gives explicit ordering guidance: 'Fetch this before authoring the definition for create_api_template / create_api_template_version.' That is a clear call condition. It omits update_api_template, which also needs a definition, so the set of consumers is not complete.

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