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

The annotations already establish that this is read-only, idempotent, non-destructive, and open-world. The description adds meaningful behavioral detail by explaining the types of analysis returned: letter grade, benchmark-weighted scores, deliverability health, insights, and recommendations.

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 two efficient sentences, front-loading the core purpose and then summarizing return contents. There is no redundant or filler language.

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 read-only analysis tool with no output schema, the description does a good job explaining what the agent will receive. It could be slightly more complete by noting the optional cost_per_email parameter or routing relative to sibling analysis tools, but the core context is present.

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 100%, so campaign_id and cost_per_email are already documented. The description does not add further meaning about the required campaign identifier or the optional cost-per-email ROI input, so the baseline score of 3 applies.

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 gives a specific verb and resource: deep-dive analysis of a single campaign's performance. It also previews the outputs, making the tool's role clear, though it does not explicitly name sibling tools like analyze_latest_campaigns or compare_campaigns.

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 phrase 'single campaign's performance' implies when this tool is appropriate, but there is no explicit when-to-use guidance, exclusions, or comparison to alternatives such as get_campaign or campaign_health_dashboard.

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