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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real behavioral value by disclosing the returned content: match counts, distinct deck and player counts, and per-character pick rates normalized to 0-1, which is important since no output schema exists.

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?

One front-loaded sentence with the key framing (single archetype, sourced from the list tool) stated first, followed by return content. The parenthetical definition of pick rate is dense but earns its place by defining a non-obvious metric.

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 no output schema, the description must carry the return-value burden, and it does describe the main fields: match counts, distinct deck/player counts, and per-character pick rates. It omits finer structural details such as whether the archetype name/id is echoed or how characters are keyed, but it is sufficient to call the tool correctly.

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% with a single required parameter, so the schema already explains that archetype_id comes from list_archetypes. The description reinforces that provenance but adds no format or constraint detail beyond it, matching the baseline 3 for schema-documented parameters.

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 and resource ("Show one archetype") and immediately anchors it against the sibling list_archetypes, making clear this is the single-item detail view versus the list. It goes further by enumerating what the item contains, so an agent can distinguish it from get_archetype_report and list_archetypes without opening a schema.

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 "from list_archetypes" establishes the required workflow: obtain an id from the list tool, then call this one for detail. It gives clear usage context but does not explicitly rule out alternatives such as get_archetype_report, so it stops short of full when/when-not guidance.

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