v2_mode

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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false). The description adds meaningful context beyond that: it reports credential-set presence "never the values", preferred API selection, and transport reachability — useful disclosure for a diagnostic tool, though it doesn't describe response shape or failure behavior.

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, front-loaded with the subject of the report and ending with the actionable call condition. The middle enumeration is slightly list-heavy but every item earns its place by naming what is returned.

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 no output schema and no parameters, the description carries the burden of saying what comes back, and it enumerates four distinct pieces of configuration state plus the failure-diagnosis use case. Adequately complete for a zero-parameter introspection tool, though it could note that all four groupings are returned together.

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 there is nothing for the description to disambiguate; the schema is trivially complete. Baseline for a no-parameter tool 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?

The description states concretely what this tool reports: read-only vs write-enabled mode, loaded credential sets, preferred API, and v1/v2 transport reachability. It effectively distinguishes itself from data-fetching siblings like v2_status and v2_get, though it uses no explicit verb (e.g., 'Get the server mode') and its opening phrase is somewhat abstract.

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?

'Call this to explain why a write was refused' gives a clear, concrete triggering condition for invocation. It stops short of naming alternatives or when-not-to-call guidance, so it is clear context without full routing rules.

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