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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description earns credit for what it adds: alphabetical ordering, one-page-at-a-time pagination, and a 30-minute cache TTL. The cache note is genuinely useful invocation context. It doesn't say whether total page counts are returned or how to detect the last page.

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?

Roughly four dense sentences, all front-loaded with scope before field details, and every sentence carries information (field names, alternative endpoint, cache window). The field enumeration is a bit compressed but not wasteful.

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?

There is no output schema, so describing the returned fields (id, name, drop_count, icons with 'four likeliest drops') is exactly the right compensation and makes the result interpretable. Combined with the annotations and the alternative-endpoint pointer, an agent has enough to call it correctly; only end-of-pagination behavior is unclear.

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%, so both parameters (page, per_page with defaults and max 200) are fully documented in the schema. The description only implies pagination via 'One page of loot sources' and adds no syntax or format detail beyond the schema. Baseline 3 is correct when the schema carries the load.

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 names the resource precisely ('Every loot source (crates, NPCs, barrels)') and scopes it to one alphabetical page. It also distinguishes itself from get_loot_table by routing per-source drop data to '/loot-tables/{id}'. It stops short of a full 5 only because the leading sentence has no explicit verb ('list'), reading more like a label than an action statement.

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?

It implicitly frames this as the browse-all path while pointing to get_loot_table for full drop tables, which gives an agent a real routing decision. It doesn't state exclusions or when to prefer a search sibling, but among its siblings none covers loot sources, so the gap is small.

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