mf_auth_start

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

With no annotations, the description carries the full behavioral burden. It does disclose meaningfully that the default mode displays an auth code to the user, but omits other key behaviors: that the auth URL is returned immediately without waiting (only in the schema param text), that the user must complete authorization out-of-band, and whether credentials are persisted for later tools.

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 tightly packed sentences with the core action front-loaded and the mode distinction immediately after. No filler, no redundancy with the schema or title.

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-required-parameter auth entry point with no output schema, the description covers the mode mechanics but not the return value (the auth URL the agent must surface to the user) nor the sequencing with mf_auth_status/mf_auth_callback. An agent would have to infer the surrounding flow.

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 description coverage is 100% with a single optional parameter, so the baseline is 3. The description adds no information about the 'wait' parameter (indeed it contradicts nothing but simply ignores it), though it does surface the non-parameter MF_REDIRECT_URI environment variable that governs behavior.

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+resource ('OAuth認証を開始します') and usefully distinguishes the two operating modes (OOB vs callback server). It never distinguishes itself from the sibling auth starters (mf_expense_auth_start, mf_accounting_auth_start) or from mf_auth_status/mf_auth_callback, leaving scope disambiguation to the naming convention alone.

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 explains how to switch modes via MF_REDIRECT_URI (default OOB vs localhost callback), which is genuine configuration guidance. However, it gives no explicit when-to-use ordering relative to mf_auth_status, mf_auth_callback, or mf_refresh_token, the natural companions in an auth flow, so usage is only implied.

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