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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the trailing 'Read-only.' largely repeats structured data. The genuinely additive part is the disclosure that each use case carries an example prompt and a page, which tells the agent what content comes back.

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?

A single front-loaded sentence with no filler; the parenthetical example list is long but earns its place by showing the breadth of the catalog an agent can expect. The redundant 'Read-only' tail is the only waste.

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 zero-parameter, no-output-schema enumeration tool, the description covers what is listed, what accompanies each entry, and the safety profile via annotations. An agent has everything needed to decide to call it and to expect the return content.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and no schema semantics to extend. Baseline 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?

The description uses a specific verb ('List') plus a defined resource ('the kinds of sites and apps GYSM plans well') and enumerates concrete examples, so an agent can tell this is a discovery/enumeration tool rather than a planning tool like plan_online_store. It stops short of naming a sibling, so differentiation is implicit rather than explicit.

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 explicit statement of when to call this versus the planning or lookup siblings, only an implied 'inspect available use cases first' reading. The examples make the tool's scope obvious, but an agent gets no stated exclusion or alternative.

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