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

Annotations already declare readOnlyHint and idempotentHint true, and destructiveHint false, so the description doesn't need to reiterate those. It adds context by naming specific outputs (revenue per campaign, per contact, average order value), which helps the agent understand what to expect. However, no mention of any side effects or limitations (e.g., data freshness, permissions) beyond annotations.

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 sentence that concisely conveys the tool's purpose and key metrics. It is well-structured and front-loaded with the core action. Every word contributes value, making it efficient and easy to parse.

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 has no output schema, the description partially compensates by listing output fields (revenue per campaign, per contact, average order value). Annotations cover safety and idempotency. For a simple read tool with only two parameters, this is minimally complete, but could include more context on data scope or granularity.

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%, with both period (enum, default 30d) and campaign_id (optional filter) well-documented. The description doesn't add new parameter semantics beyond what the schema provides, so baseline of 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?

The description clearly states the tool attributes revenue to email and lists specific metrics (revenue per campaign, per contact, average order value). It distinguishes itself from sibling tools like 'get_analytics' and 'get_campaign' by focusing on attribution, but could be more precise about what it doesn't do (e.g., raw analytics).

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 implies this is for tracking email-driven revenue, providing implicit context for when to use it vs. siblings like 'get_campaign' or 'get_analytics'. However, it lacks explicit guidance on when not to use it or mention of alternatives, which would help an AI agent decide.

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