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

Annotations already declare idempotentHint=true and destructiveHint=false, but the description adds genuinely new behavior: non-atomic partial failure with failed items reported while the rest proceed, and the guarantee that other cluster memberships are preserved. These are material semantics an agent could not derive from the annotations alone.

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?

Four short sentences, zero filler, with the primary add/remove action and cap front-loaded ahead of the secondary guarantees. Every sentence carries distinct 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?

For a mutating bulk tool with five required params, an output schema present (which covers the failed-items return), and idempotency annotations, the description covers scope, failure mode, and retry safety adequately. It omits permission requirements and whether unknown cluster IDs are silently skipped, a minor gap.

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 description coverage is 0%, so the description must compensate. It explains the operation enum values and the 100-item cap, but those are already in the schema (enum, maxItems), and it adds no meaning for organizationId, projectId, trackedQueryIds, or queryClusterIds beyond their self-evident names.

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 pair (add/remove) and both resources (tracked queries and query clusters), so the agent knows exactly what state change occurs. It is readily distinguishable from siblings like create_clusters, delete_cluster, and apply_auto_clustering, which operate on clusters themselves rather than membership.

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 clarifies the two operation modes and what is left untouched, which implies usage, but never states when to prefer this over alternatives such as update_tracked_queries or apply_auto_clustering, nor any prerequisites. Guidance is implied rather than explicit.

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