list_placements

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is clear. The description adds behavioral context by explaining that each placement's output includes how many clusters it currently selects, and how namespace filtering works. This goes beyond the annotations without contradicting them.

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 extremely concise—two lines—and front-loaded. The first sentence states the primary function, and the second clarifies the parameter. Every word is useful, with no fluff or repetition.

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?

Given the tool's simplicity (one optional parameter), the presence of an output schema, and strong annotations, the description covers all necessary context. It explains the core listing behavior, the namespace filter, and the cluster-count output. No critical gaps remain.

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 0% description coverage, so the description must compensate. It fully explains the only parameter (namespace): "limit to one namespace; empty lists across all namespaces." This provides complete semantic guidance beyond the schema's bare type/default.

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 says "List Placements and how many clusters each currently selects," which is a specific verb (list), a clear resource (Placements), and an informative output scope (cluster counts). It distinguishes itself from siblings like get_placement_decision or list_clusters by focusing on placement-to-cluster counts.

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 provides context on using the namespace parameter (limit or list all), but it does not explicitly discuss when to prefer this tool over related siblings (e.g., get_placement_decision) or when not to use it. The usage is implied from the name and description but not formally guided.

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