arch_summary

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

Annotations already declare readOnlyHint=true, so safety is known. The description adds behavioral context: 'compact' signals a high-level overview, and 'ground truth' asserts authority. This goes beyond the annotations without contradicting them.

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?

Two sentences with distinct purposes: the first lists contents, the second gives usage guidance. No redundancy, perfectly front-loaded and concise.

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 no-parameter tool, the description adequately covers what it returns and when to use it. The lack of an output schema is mitigated by the explicit content list, though a bit more detail on return format would be helpful.

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 accepts zero parameters, so the input schema fully defines the invocation. The description enriches understanding by listing the output content, which is more valuable than parameter detail.

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 this tool provides a 'compact architecture summary' and enumerates its contents (modules, route prefixes, domain entities, hotspots, visibility score). It distinguishes itself from siblings by labeling it as 'ground truth for where things live', implying a foundational overview rather than a deep-dive.

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 description explicitly says to use this 'before searching the codebase', giving clear when-to-use guidance. It does not explicitly name alternatives, but the positioning as an entry point is sufficient given the sibling tool names.

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