List User Profiles

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

No annotations are supplied, so the description carries the full burden. It usefully discloses that the result is a merged view across two storage backends and that profiles feed EER calculations, but it says nothing about ordering, whether stale virtual sessions are included, or cost of the cross-store scan.

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 stated up front and the bulleted usage block is easy to scan. Mild redundancy: the first bullet ('Discovering available user profiles') restates the opening sentence rather than adding a new condition.

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-parameter list tool with an output schema already documenting the return shape, the description supplies the one thing the schema can't: that results span virtual and persistent storage. Only the absence of annotations leaves a residual gap in side-effect/permission disclosure.

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 zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly describes a no-argument call rather than implying filtering options that don't exist.

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 names a specific verb and resource (list user profiles) plus a meaningful scope distinction: results come from both virtual/in-memory sessions and persistent database storage. That scope detail separates it from get_user_profile, though the description never names a 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?

A dedicated 'Use this tool when' block gives four concrete scenarios (discovery, multi-household management, cleanup, overview), which is stronger than implied usage. It stops short of exclusions, e.g., it doesn't say to use get_user_profile for a single profile or list_temp_sessions for non-profile sessions.

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