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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior. The description adds meaningful context beyond that: the result is saved (not recomputed), it is returned verbatim, and it includes specific data fields plus a requirement to quote numbers verbatim. It does not explain error behavior for unavailable DC counts, but the enum constrains valid inputs.

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 tightly written sentences with the core purpose front-loaded and the return payload spelled out. The word 'verbatim' appears twice, which is slightly redundant, but the total length is well matched to the tool's simplicity.

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 simple two-parameter read tool with full schema coverage and read-only annotations, the description is nearly complete. Because no output schema exists, it appropriately describes the returned fields (lat/lon, nearest city, customer assignments). Only the behavior for an unavailable saved result is left unaddressed.

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 coverage is 100% with enum descriptions for both demo_id and dc_count, so the schema already carries parameter meaning. The description reinforces that the result is scoped to 'one DC count' but adds no syntax, defaults, or constraints beyond what the schema provides.

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 names a specific verb (Return) and resource (saved greenfield result for one DC count) and previews the payload: sited DCs with lat/lon, nearest city, and customer assignments. It is distinguishable from get_opt_result and the describe/explain siblings by the 'saved greenfield result' framing, though it never explicitly names an alternative.

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?

There is no when-to-use or when-not-to-use guidance. The description implies retrieval of a stored result rather than recomputation, but it doesn't tell the agent to use list_greenfield_demos or describe_greenfield_demo first, or when to prefer get_opt_result instead.

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