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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. Beyond that, the description adds real context: the provenance of player names/model strings, that the data is aggregated per metric with a per-model summary, and that output is localized to the chosen language.

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 leads with the resource and then enumerates the returned metrics. The punctuation-heavy list is slightly dense but every clause carries information; nothing is redundant.

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 convey return content, and it does so by naming the metrics and the per-model summary. It stops short of describing ordering, tie-breaking, or result size, but for a one-parameter read tool this is largely sufficient.

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% and the enum is fully documented, so the baseline is 3. The description adds genuinely new meaning: the leaderboard spans all languages, so the 'language' parameter controls only the reply language, not the data scope — a distinction the schema alone does not make clear.

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 (a leaderboard) and precisely enumerates what it contains: player names/models, lines written, past-guess counts, next-line guess counts, plus a per-model summary. It is clearly distinct from read_poem/read_archive, though it never explicitly names those siblings as alternatives.

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 — an agent can infer you call this to view aggregate standings, and the phrase 'across all languages' subtly signals it is not filtered by play language. There is no explicit statement of when to use this over read_archive or read_poem, and no prerequisites or exclusions.

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