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

Annotations already declare readOnlyHint=true, and the description adds useful behavioral context: pagination with 'page N of M' instructions, payload size note about acceptance criteria being omitted, and the effect of passing `system`. This exceeds what annotations alone provide, though it doesn't cover all possible edge cases.

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 description is four sentences, front-loaded with the map content and followed by usage tips. Each sentence contributes necessary information about drift handling, single-system mode, and pagination, though the phrasing is slightly dense with symbols like '→' and capitalizations.

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 read-only tool with three optional parameters and no output schema, the description covers the returned fields, the special single-system payload, and pagination behavior. It is fairly complete, though the role of `project_id` remains ambiguous and no example is given.

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 schema describes `page` and `system` (67% coverage); the description enriches both by explaining the page continuation pattern and that `system` returns acceptance-criteria detail. However, `project_id` has no schema description and is not mentioned in the description, leaving a gap for that parameter.

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 clearly states the tool returns a system-to-code map with specific fields (implementing files, status, drift flag, last_commit, acceptance-evidence counts). It distinguishes from siblings by focusing on the build region map and explicitly pointing to report_drift for missing files. The purpose is specific, though it lacks an explicit verb like 'lists' or 'retrieves'.

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 provides context on when to use the tool (when you need the system-to-code map) and directs to report_drift when mapped files are gone. It also explains the mode for querying a single system via the `system` parameter and pagination for large results. However, it doesn't explicitly contrast with other sibling getters like get_system or list_systems.

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