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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety and side-effect profile is fully covered. The description adds no behavioral detail beyond the topics listed; it doesn't mention list ordering, pagination, or fallback behavior, though the schema's language parameter does document the English fallback.

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 compact single sentence that front-loads the resource ('QuoteBill's written guides') and then gives concrete examples of the guide topics. It is slightly list-like but every part contributes to clarifying what the tool returns.

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 listing tool with one well-documented optional parameter, strong annotations, and an output schema, the description plus schema covers what an agent needs to invoke it correctly. The only minor gap is that the description does not explicitly say the tool returns a list, but the title and output schema make that apparent.

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?

There is only one optional parameter and the input schema documents it 100%, including its enum values, default, and fallback behavior. The description's mentions of German, Japanese, and Korean map only loosely to the language parameter and add no operational semantics beyond the schema, so baseline 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 title and name clearly state the action: 'List the how-to guides.' The description adds the resource's scope—QuoteBill's written guides covering quote-to-invoice conversion, country-specific invoice requirements, payment terms, numbering, and currency—which distinguishes it from siblings like list_reference and search_templates. It is not a 5 because the description itself is a fragment and relies on the title for the explicit verb.

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 when to use the tool: when a user wants QuoteBill's written how-to guides on invoice topics. However, it provides no explicit guidance about when to prefer list_reference, get_template, or search_templates instead, and gives no exclusion criteria or alternate routing.

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