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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description doesn't need to repeat those. It adds value by disclosing the concrete return fields (genome, genomeHash, expiresAt), which are not present in any structured form since there is no output schema. It doesn't cover error/not-found behavior, but that's a minor gap for a simple getter.

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?

One sentence with zero filler, front-loaded with 'Read-only' and immediately stating what is returned. Every part earns its place.

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?

Complete for a single-parameter getter: the schema covers the ID format, annotations cover safety and idempotency, and the description covers the return payload. No output schema exists, but the description names the three return fields, so an agent has everything needed to invoke it correctly.

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%: design_id is fully documented with type, pattern, and an example. The description adds no additional parameter-level meaning, 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?

States a specific operation ('Returns one design by design_id') with a clear resource and scope. It also lists the returned fields, making it readily distinguishable from sibling getters like get_forest and list_trees.

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?

Clearly implies when to use it: when you have a design_id and need that specific design's genome, genomeHash, and expiresAt. It doesn't explicitly name sibling alternatives or exclusion conditions, but the context is clear and unambiguous.

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