Interactive Browser Login to Volleymetrics

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

Annotations only declare it is non-readonly, open-world, non-idempotent and non-destructive; the description goes far beyond by naming the side effects (visible Playwright window, Bearer tokens written to ~/.volleymetrics_mcp/auth_state.json with 0600 permissions plus OS Keychain, and a full query-cache clear), the zero-password-exposure guarantee, and the auto-close/timeout behaviour. Success and failure return states including the missing-Chromium remedy are also disclosed, so no annotation contradiction arises.

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?

Headings, bolding and the front-loaded contrast sentence make it scannable despite its length, and every section maps to something an agent needs. It is slightly over-written — the Returns section restates failure modes already implied and the opening sentence is dense — but nothing is truly wasteful for a tool with this many side effects.

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?

A one-parameter, no-output-schema tool whose annotations are sparse is fully covered here: triggers, exclusions, side effects on disk and keychain, credential handling, timeout behaviour, and both success and failure outputs are all stated. Nothing an agent needs to decide whether and how to call it 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?

Schema coverage is 100% and the single parameter is self-explanatory, yet the description adds real decision guidance beyond the schema: keep the default 300s when the user must approve mobile 2FA, drop to 60-120s for quick password-manager autofill. That is workflow meaning the schema's min/max/default numbers cannot convey.

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 opening sentence pairs a specific verb (launch) with the resource (interactive desktop Chromium window for Volleymetrics/Hudl auth) and explicitly contrasts itself with the sibling `refresh_volleymetrics_session` as headless env-var-based. An agent can distinguish this from every sibling list tool without opening a 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?

Dedicated 'When to Use' and 'When NOT to Use' sections give concrete triggers (recover from a 401, initial setup without plaintext passwords) and explicit exclusions (don't call proactively; don't use in headless CI without a display, use refresh_volleymetrics_session instead). The alternative is named with the condition that selects it.

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