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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds behavior the annotations do not: that archived systems are included in results and marked via archivedAt, and that the connected app names can be used by SetLatch for lookups. It does not discuss pagination or result size, which keeps it from a 5.

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 tight sentences, front-loaded with what the tool returns, followed by the archived-case edge and then usage routing. The parenthetical asides are informative rather than wasteful, though the first sentence is dense and could be split for faster scanning.

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 one-parameter read tool with no output schema, the description covers the important ground: what is returned, the archived-vs-active distinction, and when to call it. It omits nothing an agent would need to invoke it correctly, though a note on result cardinality or ordering would round it out.

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 single 'site' parameter is fully documented in the schema itself, including the slug/id/name alternatives. The description only implies site scoping ('the systems a site keeps') and adds no format or resolution detail beyond the schema, so the baseline of 3 applies.

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 a specific resource and enumerates its contents: the systems a site keeps personal data in (CRM, email marketing, payments), each with notes and the names of connected apps. It also states the archived-system marker (archivedAt), so an agent knows exactly what this returns and can tell it apart from add_data_map_system and update_data_map_system.

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 explicit routing instructions with named alternatives: use before add_data_map_system to avoid duplicates, and use to obtain the system_id that update_data_map_system requires. Both the when and the specific sibling that depends on it are stated, leaving nothing to inference.

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