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

Annotations already cover readOnly/openWorld/destructive, so the bar is lower; the description adds real context by disclosing that the result is scoped to the OAuth session and that redaction is display-only — "tool result fields remain available for the workflow." That is a non-obvious behavioral guarantee the agent would otherwise have to infer, though no return-field inventory is given (the output schema covers that).

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?

The purpose is front-loaded in sentence one, but roughly 80% of the text is reply-formatting policy (omit IDs, never redact, show only when asked, show only what's needed) that repeats itself across several sentences. It is on-topic but bloated for a zero-parameter read.

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 zero parameters, a 100%-covered schema, an output schema, and safety annotations, the remaining gap is small; the description supplies the session scoping and the display policy an agent would otherwise get wrong. It is complete enough to invoke correctly without further documentation.

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?

This tool takes zero parameters, so the baseline of 4 applies; there are no arguments whose semantics need explaining. The description correctly indicates nothing is needed beyond the ambient OAuth session context.

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 first sentence gives a specific verb and resource: 'Return the APIXO profile connected to this OAuth session.' The scope (OAuth session, not an arbitrary user lookup) distinguishes it from the generation-focused siblings, though the description never names or contrasts any sibling explicitly.

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?

Guidance is given for presentation choices ("include its email only when relevant", "Show an identifier only when the user explicitly asks"), but nothing says when to call this tool — e.g., at session start to learn the connected account. Usage is implied rather than stated, and no alternatives or exclusions are named.

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