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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds that the report is 'stored', indicating a pre-existing snapshot rather than live computed data, and it discloses the content categories. No behavioral contradictions are present.

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 compact sentence that front-loads the action and object, then lists report sections without filler or redundancy.

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 read-only tool with two well-documented parameters, safety annotations, and no output schema, the description covers the core purpose and return contents. It leaves minor ambiguity about the exact response shape and the meaning of 'the three decisions', but this is a small gap for an otherwise 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 fully documents both parameters: site_id is a UUID from list_sites and month uses the yyyy-mm pattern. The description mentions 'website and month' but adds no format, derivation, or usage detail beyond the schema. With 100% schema coverage, the baseline 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 states a specific verb ('Return') and resource ('stored monthly report content'), and enumerates the report sections: key numbers, health, AI visibility, fixes, goals, and the three decisions. This clearly separates it from sibling tools that return individual metrics, though it does not explicitly name an alternative.

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 'stored monthly report content' implies this tool retrieves a pre-generated aggregate report, and listing its sections hints that it is an umbrella alternative to several metric-specific siblings. However, there is no explicit when-to-use, when-not-to-use, or alternative tool guidance.

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