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

Annotations already mark this as destructive and idempotent, but the description adds crucial behavioral context: the replacement is additive to the workspace list, it cannot release workspace exclusions, and the list is wholly replaced rather than merged. This meaningfully expands on what the annotations alone convey.

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?

Every sentence earns its place. The core operation is stated first, followed by critical caveats about additive behavior, complete-list replacement, clearing, and verification. No redundant or filler content exists.

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 destructive, idempotent replacement operation with no output schema, the description fully covers what an agent needs to know: how to invoke it correctly, what the edge cases are, and how to inspect the resulting effective exclusions. Nothing important is missing.

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 schema already documents exclusions and workspaceId, but the description adds important meaning: the exact replacement semantics, that [] clears the list, that entries match campaignstack_get_exclusions shapes, and how to interpret the effective merged result. signalAgentId is not described in the schema or description beyond its name, but its role is clear from context and the read-back instruction.

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 opens with a specific verb and resource: 'Replace a signal agent's own (level-1) exclusion list.' It clearly distinguishes itself from related tools like campaignstack_get_exclusions and campaignstack_toggle_exclusion by emphasizing this is a full replacement operation, not a read or toggle.

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 gives explicit when-to-use and when-not-to-use guidance: it instructs to pass the complete list rather than a delta, clarifies that [] clears the list, and explains that workspace-level exclusions must be edited via the workspace list instead. It also tells the agent how to verify the merged result by reading campaignstack_get_exclusions with level=effective.

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