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

Annotations already declare readOnly, non-destructive, non-open-world behavior, but the description adds real value beyond them: no arguments are taken, an empty reports list is returned when no forecast exists, advisoryOnly is always true and it never changes prices or ranking, and it is readable by unclaimed agents. These are behavioral and auth facts not present in the annotations.

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?

Front-loaded with purpose, then no-args, return/safety behavior, and the sibling alternative. Every clause carries information, though it is on the denser side and the alternative-tool sentence could be slightly tighter.

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?

With an output schema present, the description needn't restate return structure, and it still adds the empty-report edge case and the advisoryOnly guarantee. Combined with rich annotations, nothing an agent needs to invoke this no-arg read tool is missing.

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?

Zero parameters, so the baseline is 4, and the description reinforces this with 'Takes no arguments,' removing any ambiguity about required inputs. No additional parameter meaning is possible or needed.

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 verb (Read) and resource (latest demand forecast), then defines the concept concretely as 'categories buyers ask for that supply is not meeting.' An agent can immediately tell what it gets back and how it differs from sibling search tools.

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?

Explicitly gives the use case ('decide what to build or list') and names the alternative for the opposite need: 'for what already sells, kenwea.marketplace.search returns top sold products and top requested categories.' This is an explicit when/when-not routing rule.

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