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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real context beyond the schema: the serving host (mcp.httpstatus.com) and that it returns both a live URL and an inline sample. It does not state expiry or persistence of the URL, but the safety-critical behavior is clear.

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 tightly packed sentence that front-loads the action and output, then the modifiers. No filler or redundancy; every clause carries information.

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 only two parameters, no output schema, and no nested objects, the description covers what the tool returns (a URL plus inline sample) and the conditional count rule. The only omission is any hint about how this relates to the sibling URL-generating tool.

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 50% (count documented, kind is an enum). The description adds meaning beyond the schema by stating that only plural kinds accept count and restating the max of 50, telling the agent the count is conditional on kind rather than always applicable.

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 states a specific verb and output ('Return a live URL ... serving placeholder JSON') and enumerates the six kinds, so the agent knows exactly what it produces. It does not explicitly differentiate itself from the similar sibling generate_status_url, which is the only gap.

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?

Usage is implied by the listed kinds and the note that plural kinds accept count, but there is no explicit when-to-use guidance or exclusion relative to generate_status_url, the closest alternative. An agent can infer the context but is not told when to prefer this over siblings.

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