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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description still adds genuinely new context the annotations cannot express: 'Discovery only — this does not consume API credits', which is a material cost consideration for an agent deciding whether to call it. It omits any note on result size or pagination, keeping it below a 5.

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?

Three short sentences, front-loaded with what it returns, followed by when to use it and the cost caveat. No filler and no restating of the tool name.

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 the description needn't explain return values, and the zero-param schema needs no elaboration. What is missing is only a pointer to the natural follow-up tool (list_endpoints / get_endpoint_schema), which would make the discovery workflow fully closed-loop.

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. It correctly presents itself as an unfiltered full listing, which is the only semantically relevant statement for a no-arg tool.

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 and resource ('List every platform Scraping Daddy can scrape') plus the shape of the result ('with a short description'). This is clearly distinguishable from siblings like list_endpoints, get_endpoint_schema, and api_request, which operate on endpoints or make calls rather than enumerate platforms.

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 names the triggering condition: 'Start here when the user asks SD for live data and the endpoint is not known yet.' That gives a clear entry-point rule, though it stops short of naming list_endpoints/api_request as the required next step, so the agent must infer the follow-on tool.

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