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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so safety is covered. The description adds the useful detail that returned rules include status, conditions and action, but says nothing about volume, pagination, or whether all rules or only active ones are returned.

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?

A single compact sentence with no filler, and the resource is front-loaded. It is slightly under-specified rather than padded, which costs it nothing in wastefulness but leaves a clause of explanatory example that could have carried usage guidance instead.

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 zero-required-parameter read tool with full schema descriptions and no output schema, the definition is adequate but thin. An agent still has to infer that this reads rules rather than managing them, and gets no hint about result size or scope across accounts.

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 coverage is 100%, and the folder/account/language/detail parameters are already fully documented, including the summary-vs-full guidance. The description adds nothing beyond the schema, so 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?

Names a specific resource (automated rules on the ad account) and enumerates the payload the agent will see (status, conditions, action), with a concrete example of a rule. It never uses an explicit verb like 'list' or 'retrieve', so the read-only nature is only inferred from sibling names like meta_create_rule and meta_delete_rule.

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?

No statement of when to reach for this tool versus meta_create_rule, meta_delete_rule, or any of the many meta_* performance tools. The presence of create/delete siblings makes the listing role guessable, but the description never confirms it or says what question it answers.

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