list_sites

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It states that the tool returns site IDs, domains, and tracking keys, but does not mention any important traits such as authorization requirements, rate limits, pagination, or whether the list is exhaustive. Basic information is present, but not enough for full transparency.

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?

The description is very concise with two sentences, front-loading the verb and resource. It avoids unnecessary detail while still providing key return fields. However, it could be slightly more structured by separating the purpose from the returns.

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?

The tool is simple (0 parameters, no output schema, no nested objects). The description is sufficient for its low complexity, clearly stating what and where it lists. It could be improved by specifying if all sites are returned or if there are any limitations.

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 input schema has zero parameters and 100% schema description coverage, so the baseline is 4. The description does not need to explain parameters since there are none, and it correctly focuses on what the tool returns.

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 the specific verb 'list' combined with the resource 'sites' and includes the scope 'in your Measure.events account'. It clearly explains what the tool does and distinguishes it from siblings like get_pageviews, which focus on specific metrics rather than a general list.

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?

The description implies when to use the tool (to list all sites), but it does not explicitly state when not to use it or mention alternative tools. Given the sibling tools have different purposes, the usage is clear enough, but lacks explicit exclusions or context.

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