What the connected CalDAV server can do

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context by explaining exactly what the server reports and why it is useful for diagnosing differences in CalDAV implementations, which goes beyond what annotations convey.

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 with no filler. The first sentence lists the concrete outputs, and the second gives the diagnostic use case, making the purpose immediately apparent. Every phrase 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?

For a zero-parameter, read-only capability probe with an output schema and safety annotations, the description is fully complete. It states what the tool reports, why it matters, and when to run it. Nothing essential 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?

The tool has zero parameters and schema description coverage is 100%, so there is no parameter burden for the description. Baseline 4 is appropriate here; the description correctly focuses on behavior and outputs rather than parameters.

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 names a specific verb ('Reports') and a concrete resource: the connected CalDAV server's capabilities, compliance tokens, accepted components, and optional feature availability. It clearly distinguishes itself from the sibling CRUD/search tools by focusing on server-level capability discovery rather than individual calendar objects.

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 situational guidance: 'The first thing to run when something behaves differently than expected.' This tells the agent when to invoke this tool. It does not enumerate sibling alternatives or say when not to use it, but for a zero-parameter diagnostic tool, this is sufficiently clear context.

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