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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, covering safety. The description adds a usage-oriented behavioral cue ('Call this first if docs tools seem unavailable') but doesn't disclose what the response contains or how availability is determined, so it adds limited value beyond the annotations.

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 concise sentences: the first states the core purpose, the second provides usage guidance. No superfluous words or repetition, and the most important information is front-loaded.

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 zero-parameter health check tool, the description fully covers purpose and when to invoke it. Even without an output schema, 'availability' is self-explanatory, and the 'call this first' guidance is sufficient for an agent in context.

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 has 0 parameters, and schema coverage is trivially 100%. Per the baseline for 0-param tools, a score of 4 is appropriate; the description doesn't need to explain parameters because there are none.

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 a specific verb-resource pair ('Check SDK documentation availability') and distinguishes this tool from siblings like docs_list_tools and docs_getPage by framing it as a health check. The added guidance 'Call this first if docs tools seem unavailable' reinforces its diagnostic 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?

It explicitly says when to use the tool ('if docs tools seem unavailable') and instructs to call it first, giving clear context. It does not list alternative tools or when-not-to-use, but the trigger condition is unambiguous.

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