adtCompatibiliyGraph

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description doesn't need to repeat that. It adds the diagnostic purpose and the fact it's about protocol versions, which is useful. However, it doesn't describe the output format or whether any parameters are needed (though there are none). The description adds context beyond annotations but could be richer.

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 a single, efficient sentence that conveys the purpose and usage context without any fluff. It is front-loaded with the main purpose and then clarifies the use case. Every word earns its place.

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's simplicity (zero parameters, no output schema, read-only annotations), the description is adequate for an agent to know when to invoke it)Skip. It tells the agent the trigger (unsupported version call) and what it provides (compatibility graph). Could perhaps mention that it requires no input, but that's inferable from the schema.

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 zero parameters, so the description doesn't need to explain any. The 'Diagnostic' qualifier adds context about what the tool returns (diagnostic info), which is helpful. Since there are no parameters, the description fully covers any semantic need.

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's purpose: it provides the ADT compatibility graph of protocol versions for collections. It is specific about the resource (ADT compatibility graph) and the diagnostic context (for a call refused as unsupported version). This distinguishes it from siblings, though it doesn't explicitly name alternatives.

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 clearly specifies when to use this tool: when a call is refused due to an unsupported version. This gives the agent a concrete trigger condition. It does not explicitly mention not using it in other scenarios, but the diagnostic context is clear enough.

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