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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so 'Changes nothing' largely restates them. However, the description adds genuine value by disclosing the shape of the response (id, action, expression) in the absence of an output schema, which the annotations do not cover.

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, front-loaded sentence with zero filler; every clause (scope, returned fields, no side effects) earns its place.

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 list tool with full annotation coverage and a fully documented parameter, the description is largely sufficient, covering scope and return fields. It could note pagination or result ordering, but nothing critical is missing.

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?

Only one parameter exists and its schema description coverage is 100%, so the schema fully explains the 'zone' argument. The description adds no extra meaning about the parameter, making the baseline 3 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?

States a specific verb ('List') and resource ('custom firewall rules and rate limits of a Cloudflare zone'), and even names the returned fields (id, action, expression). This cleanly separates it from the sibling mutation tools cf_firewall_add and cf_firewall_remove.

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 'Changes nothing' implies a safe read operation, and the name distinguishes it from the add/remove siblings, but there is no explicit when-to-use or when-not-to-use guidance and no named alternatives. Usage is only implied.

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