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

Annotations already cover read-only, idempotent, non-destructive, and closed-world behavior. The description adds useful context by enumerating the returned fields, which matters because there is no output schema. It does not mention error behavior for missing IDs or rate limits, but the annotations lower the bar.

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?

Two tightly written sentences. The primary purpose and returned fields are front-loaded, and the final sentence efficiently routes the agent to the stats sibling without wasted words.

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 simple one-parameter read tool with no output schema, the description is nearly complete: it lists the fields an agent can expect and points to the correct alternative for performance data. A minor gap is the absence of any note about what happens when the campaign ID does not exist.

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 one parameter is fully documented in the schema, including that it is a numeric campaign ID sourced from directiq_list_campaigns. The description only says 'by ID' and adds no format or validation detail beyond the schema, so the baseline 3 is appropriate.

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 and resource ('Get one campaign by ID') and enumerates the exact fields returned, including name, type, status, subject, sender, target lists/segments, template ID, recipient count, and scheduled send time. It distinguishes itself from directiq_campaign_stats by explicitly routing performance metrics elsewhere.

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?

Explicitly says to use directiq_campaign_stats for opens, clicks, and other results, which is a clear alternative. However, it does not mention directiq_list_campaigns as the source of IDs in the description (that appears only in the schema), nor does it discuss when to use directiq_campaign_report.

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