List hosted tools

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered structurally. The description adds two genuinely useful facts beyond that: it returns a Markdown table, and it does not invoke the listed tools because they only run on the hosted server. That is real added context, but with the annotation bar already low and no information on catalog size, pagination, or freshness, a 3 fits.

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 tight sentences, front-loaded with what is listed and followed by the use case and the scope caveat. The URL is the only element that could be trimmed, though it arguably helps the agent reference the server; nothing else is filler.

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 zero parameters and no output schema, the description does the necessary work by naming the return format (Markdown table) and clarifying that the listed tools are not executed here. The main remaining gap is the absence of any sense of catalog size or what a table row looks like, which matters mildly for an agent deciding whether to call it.

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 no parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly implies a zero-argument call by not referencing any inputs.

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 the tools of the hosted X Ads MCP server by AdKit'), plus the endpoint URL and output granularity ('one line on what each tool does'). This is clearly distinct from siblings like list_ad_platforms or get_faq, which deal with platforms and documentation rather than the hosted tool catalog.

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?

Gives an explicit use case: 'Use this to explain what an agent can do with ad accounts after connecting.' It also rules out a mistaken interpretation ('It does not call those tools'), which effectively serves as a when-not clause. It stops short of naming which sibling to use instead for adjacent questions, so it is clear context rather than full routing guidance.

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