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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It lists the returned metrics but fails to mention that this is a read-only operation, any authentication requirements, rate limits, or error behavior. For a read tool, this is a notable gap.

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 a single concise sentence that efficiently communicates the tool's purpose. It is front-loaded with the verb and lists the metrics, containing no redundancy or fluff.

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?

With no output schema, the description partially compensates by listing the metrics returned (sent, opens, clicks, etc.). However, it lacks details on the response structure, pagination, or additional metadata. Overall, it is fairly complete for a simple retrieval tool.

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 input schema has 100% documentation coverage with a single parameter 'campaign_id' described as 'ID de la campaña.' The description does not add any extra meaning or constraints beyond the schema, so it meets the baseline but does not exceed it.

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 it retrieves real metrics for a campaign, listing specific metrics like sent, opens, clicks, etc. The verb 'get' and resource 'campaign stats' are unambiguous, and it effectively distinguishes from sibling tools like list_campaigns (which lists campaigns) and account_stats (likely account-level stats).

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 no guidance on when to use this tool versus alternatives. While the purpose is clear, there is no explicit mention of context, prerequisites, or exclusion of other tools. For example, it does not differentiate from account_stats or list_campaigns in terms of use cases.

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