yandex_auth_start

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

Annotations declare readOnlyHint=false, openWorldHint=false, and non-idempotent. The description adds genuinely useful behavioral detail: MCP URL elicitation when supported, the client_id/YANDEX_OAUTH_CLIENT_ID fallback, and the guarantee that no token appears in output. It does not state side effects of re-invocation or flow expiry, keeping it below 5.

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?

Three dense sentences, each front-loading a key fact: what it returns, the elicitation behavior, and the credential fallback. No filler.

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?

An output schema exists, so return-shape detail is not required, and the description covers the critical return values and credential requirement. However, with 0% parameter coverage and a sibling yandex_auth_finish that continues this flow, the description lacks sequencing/next-step context and leaves four parameters unexplained.

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 0% across 5 parameters, so the description must compensate. It only addresses client_id (and its env-var alternative); scope, account, services, and client_secret are completely undocumented in both schema and description, leaving most parameters semantically opaque.

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 a specific verb and resource ('Start Yandex OAuth device-code flow') and names the exact return ('verification URL + user_code'), clearly distinguishing it from siblings like yandex_auth_finish and yandex_auth_status.

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?

It implies this is the entry point of the auth flow and mentions client_id/YANDEX_OAUTH_CLIENT_ID, but does not explicitly state when to use it versus yandex_auth_status or yandex_auth_finish. Usage is implied by the flow context, not spelled out.

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