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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds that output contains tradeoffs, questions and a Mermaid diagram, and that provider remaps AWS services to other clouds. It does not explain what 'questions' means concretely or whether pattern coverage is exhaustive, but for a read-only lookup this is solid added context.

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, front-loaded with the action and the primary selector; no filler. The second sentence is slightly compressed to the point of being terse, but nothing is wasted.

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?

An output schema exists, so return shape need not be spelled out (the description does anyway). However, with 0% schema coverage and a mandatory free-text workload parameter left undefined, the definition does not fully equip an agent to invoke it correctly on the first try.

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 0%, so the description must compensate. It clarifies pattern ('explicit workload pattern') and gives provider real semantics ('maps the AWS services to Azure, GCP, OCI or open source equivalents'), but the required 'workload' string (up to 4000 chars) is never explained — the largest gap, since an agent cannot tell whether it wants a name, a narrative, or constraints.

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?

A specific verb and resource ('Select a reference architecture') scoped by 'explicit workload pattern', plus a note that the result includes tradeoffs, questions and Mermaid. It is distinguishable from diagram-oriented siblings like architecture_diagram or c4_model, though it never names them explicitly.

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?

'By explicit workload pattern' implies the tool is used when a workload maps to a known pattern, and the enum of patterns reinforces that. There is no statement of when NOT to use it, no prerequisites, and no pointer to siblings such as architect_panel or service_equivalents that overlap with provider mapping.

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