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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states that the tool returns only counts, not individual-level data, which is a key behavioral trait. It also implies read-only behavior by describing a reconcile/aggregate function. While it doesn't mention side effects or permissions, the disclosure of output scope is valuable and exceeds a baseline.

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 sentences that front-load the purpose and immediately clarify the limitation. Every word earns its place, and there is no fluff or redundancy. It is appropriately sized for a simple tool.

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 (two required parameters, no output schema), the description adequately conveys what the tool does and what it returns. It clarifies the scope and the nature of the output (counts only). It doesn't mention prerequisites or errors, but for a read-only report tool this is sufficient. A 5 might be warranted if it specified return structure or error cases, but it's not necessary.

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 covers both parameters with descriptions ('Campaign ID' and 'Active organization ID'), achieving 100% coverage. The tool description adds no additional meaning beyond that, so it does not elevate beyond the baseline. It doesn't clarify formats, relationships, or usage nuances for the parameters.

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 clearly states the tool's purpose with the verb 'Reconcile' and the resource 'campaign deliveries and feedback.' It also explicitly distinguishes this tool from any that would provide per-person open details, which helps differentiate it from sibling tools like commsharbor_delivery_events or commsharbor_campaign_get. The scope is unambiguous.

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 clear context on when to use this tool: when aggregate counts are needed. It also gives an explicit exclusion: 'Which specific person opened what is not something this API answers,' which tells the agent this tool is not suitable for individual-level queries. However, it does not name alternative tools for that need, so it falls slightly short of a 5.

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