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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description's added value is the hard-coded one-week lookback window, which is genuinely beyond the annotations. It says nothing about ordering, result volume, or what a 'session' record contains.

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 front-loaded sentence identifying the resource, the time window, and the motivation, with no filler. Nothing could be removed without losing information.

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 output schema, the description is the only place an agent could learn what comes back, and it stops at 'sessions over the last week' without describing the shape of a session (fields, ordering, volume). For a zero-parameter read tool the burden is light and the time scope is covered, but the return-value gap keeps it at minimum-viable.

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 the baseline is 4 and there is no parameter meaning the description could add. The description correctly implies the only 'input' is the fixed one-week time window, which is consistent with the empty schema.

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?

States a specific resource (the user's Reulay sessions) and a concrete scope (the last week), plus the agent-facing intent of seeing activity and frequency. The retrieval verb is only implied by the name, and no sibling tool is named as a contrast, but the resource+scope pairing is specific enough to distinguish it from action-oriented siblings like start_experience or complete_journey.

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?

The clause 'to see what they've been doing and how often' implies the use case — summarizing recent activity — but there is no explicit when-to-use, when-not-to-use, or named alternative among the many sibling tools. The agent must infer that this is the right tool for history questions rather than, say, get_mindset_profile or get_today_feed.

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