xql_nl_reference

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

With no annotations, the description carries the burden of disclosing behavior. It states the operation is a fetch (read-only) and describes the content and purpose. It doesn't mention potential absence of side effects or error behavior, but the simple retrieval nature is reasonably transparent.

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 two sentences, with no fluff. The first sentence packs concrete examples of what the reference contains; the second provides direct usage guidance. Every phrase earns its place relative to the tool's simplicity.

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's simplicity (0 params, no output schema, no annotations), the description is complete: it states the return type (reference document), key contents, and when to call it. It also references sibling tools appropriately, fully covering the context needed for correct use.

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 tool has zero parameters, and the baseline for 0-param tools is 4. The description doesn't need to explain parameters; the schema confirms no inputs. The description adds semantic value by explaining the tool's role, which is sufficient.

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 fetches the XQL natural-language reference document and specifies its contents (mapping retail phrasing to syntax, hard limits). It distinguishes from siblings (xql_validate/xql_explain/xql_run) by positioning itself as the reference lookup rather than an execution or validation tool.

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?

Explicit usage guidance is provided: call before writing a query, or after sibling tools return isError: true. This directly addresses when to use this tool versus the alternatives, giving clear context and an actionable trigger.

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