api_version

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context beyond annotations: the endpoint is free and requires no API key, which affects auth handling before 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?

Two short fragments, front-loaded with what is returned and followed by the cost/auth caveat. Nothing extraneous; every clause carries information.

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 trivial zero-param read with no output schema, the description covers what is returned at a high level (version and deployed build) and the auth/cost posture. It stops short of describing the response shape, which is the only minor gap given there is no output schema to defer to.

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 zero parameters, so per the rubric the baseline is 4. There are no input semantics the description needs to explain, and it correctly does not attempt to.

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?

States a specific resource (the API's version) and adds scope beyond the name by including the deployed build. Siblings are unrelated resources, so no explicit differentiation is needed, but the description could be clearer that this is a simple read-only status lookup.

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?

"Free, needs no key" gives prerequisite context (no authentication required), which helps an agent decide it can call this cheaply. However there is no when-to-use versus alternatives guidance and no stated exclusions; usage is only implied for a zero-arg informational endpoint.

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