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

Annotations only declare openWorldHint=false and destructiveHint=false, so the description usefully adds that provider keys are never returned, that secrets are set out-of-band, and that the sender action requires an admin-scoped token. That is real disclosure beyond the structured fields. It does not spell out that `sender` overwrites the existing sender name, which is a mild but relevant mutation detail.

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 short sentences with no filler, and the most important constraint (no provider connection through chat) is placed prominently. The opening clause is slightly roundabout rather than a direct verb-resource statement, costing it the top mark.

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 values need no explanation, and all five parameters are fully documented in the schema. The description covers what the schema cannot: permission requirements, secret-handling boundaries, and the fact that provider keys are excluded from the response. Nothing an agent needs to call this correctly 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 description coverage is 100% and the enum already documents what `status` and `sender` do, including the callback URL and per-parameter notes. The description adds no syntax, format or defaulting detail beyond that. Baseline 3 is appropriate when the schema carries the full parameter burden.

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 names the resource (the app's user sign-in configuration) and the two things it exposes: enabled state and the email sender name. It also implicitly distinguishes itself from sibling key-management tools by stating provider keys are never returned and that provider wiring happens elsewhere. The elliptical phrasing "what is enabled" leaves the read half slightly softer than the write half, which the schema has to disambiguate.

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 gives a concrete when-not-to-use: connecting Yandex, VK ID or Sber ID cannot be done here and must go through the dashboard or `layero data auth provider set`. It also flags the admin-scope prerequisite for the sender action. It stops short of explicitly naming a sibling alternative for reading keys or grants, so routing is clear but not exhaustive.

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