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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered and the description need not restate it. The description adds a small amount of behavioral nuance by scoping results to 'active source revisions', but says nothing about scope limits, pagination, or what is excluded from the catalogue.

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 that names the discovery verb first and then the resources returned. There is no filler, redundancy, or trailing boilerplate to trim.

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?

With an output schema present, the description is not obliged to explain return values, and the enumerated resource kinds give the agent enough to know what it will receive. The only real gap is the absence of sibling routing guidance, which is a usage concern rather than a completeness one.

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 takes zero parameters, so per the rubric the baseline is 4. No additional parameter meaning is needed or expected, and the description correctly avoids inventing filter options that the schema does not expose.

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 verb 'Discovers' plus the enumerated resource set (factions, mission packs, rule documents, reference kinds, active source revisions) makes clear this is a catalogue-enumeration tool rooted in the 'Praetorium reference' domain. It does not, however, differentiate itself from siblings like list_factions, list_units, or search_reference, which sound like overlapping listing operations.

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?

Usage is only implied: 'Discovers available...' suggests this is the browsable entry point for the catalogue, but there is no explicit when-to-use statement, no mention of prerequisites, and no routing guidance versus get_reference, get_reference_record, or search_reference. The agent must infer this is a discovery-first call.

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