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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds real context by explaining the outbound call to the IdP discovery document and that it relies on stored settings (which explains the zero-parameter design), but it says nothing about failure modes, timeout behavior, whether a result is persisted, or auth requirements.

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?

A single sentence that front-loads the action and ends on the outcome. No filler, no restatement of the 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?

With no parameters and no output schema, the description carries the return-value burden and does sketch it ('report whether it answers'), though it does not say whether the report is a boolean, a status code, or an error detail. For a zero-input read-only probe, this is close to complete.

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?

The tool takes no parameters, so the baseline is 4. The description usefully accounts for that absence by noting the settings are stored, so an agent does not hunt for an input it must supply.

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?

Specific verb (fetch), specific resource (the identity provider's discovery document), and a stated outcome (report whether it answers). It is clearly distinguishable from sso_get by virtue of being a live probe rather than a config read, though the description never names that sibling to make the contrast explicit.

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?

Usage is implied rather than stated: the mention of 'the stored settings' signals this is run against an already-configured SSO setup, so it fits a verify-after-configuring flow. There is no explicit when-to-use, when-not-to-use, or reference to sso_get as the alternative.

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