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

Annotations already cover safety (read-only, idempotent, non-destructive), and the description adds meaningful behavioral context by listing the contents of the response: request flow, reference scenario, KPIs, cost & scaling, and composed patterns/knowledge. It also communicates the prerequisite that a slug must come from prior search/list usage.

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 no filler: the first states the action and result, the second gives the prerequisite workflow. The parenthetical list of contents is compact and informative without bloating the description.

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 single-resource fetch tool with a rich output schema and strong annotations, the description is complete. An agent knows what it retrieves, when to call it, and what prior step must happen first; the schema covers parameter details.

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 input schema already has 100% description coverage, including an example slug and a locale enum with default behavior. The description reinforces that the slug is the lookup key but adds little beyond the schema, so the baseline of 3 is appropriate.

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 states a specific verb ('Get') and resource ('one reference architecture by slug'), and enumerates what the returned architecture includes. This clearly distinguishes it from sibling list_architectures and search tools, which operate over collections rather than a single fetched item.

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 tells the agent when to use this tool: after `search` or `list_architectures` has produced a slug. This gives a clear workflow and names the relevant alternatives, so the agent knows this is the follow-up fetch step, not a discovery tool.

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