Refresh Volleymetrics OAuth Session

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

Annotations declare a non-read-only, open-world, non-idempotent operation but say nothing about side effects; the description fills that gap by disclosing the password-grant request, headless Playwright fallback, persistence of the JWT to OS Keychain and `.env` with `chmod 0600`, and conditional cache clearing. It also states the zero-network-call behavior when credentials are absent, which is exactly the kind of pre-call safety context annotations cannot 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?

Well front-loaded and organized under scannable headings, with the key differentiator in the first sentence. It is somewhat long for a two-parameter tool, and the 'credentials missing' condition is restated three times (When NOT to Use, Fallback Guidance, Returns & Error States), which is mild redundancy.

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 mutation-style auth tool with no output schema, the description covers what the agent needs: trigger conditions, side effects, parameter choice, success confirmation format (masked JWT), and the actionable error path. Nothing material is left to inference.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds decision-level meaning for `clear_cache` (set True when recovering from an auth error or switching accounts, False to retain 7-day cached match data) that goes beyond the schema's mechanical 'clears the cache after minting' wording. The `timeout_seconds` parameter is never mentioned in the description, which keeps this from a 5.

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 verb and resource (headless OAuth 2.0 token refresh for the Volleymetrics session) and immediately contrasts it with the sibling `login_to_volleymetrics`, which is described as the interactive desktop-browser alternative. An agent can distinguish the two without opening either schema.

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?

Provides explicit 'When to Use' and 'When NOT to Use' sections, naming the exact conditions (headless/automated environments with `.env` credentials vs. password-manager/SSO/2FA users) and pointing to the concrete alternative tool. It also warns against looping on the 'Interactive Login Recommended' result.

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