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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context: the 7-day window, pagination, and a summary of fields returned per leader (rank, name, username, country, total and daily-average time, top 3 languages), which matters 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?

Dense and front-loaded: purpose first, filters and paging second, return shape third. The trailing 'GET /leaders.' is minor API trivia but harmless, and every sentence otherwise earns its place.

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?

For a 5-parameter, no-output-schema tool the description is nearly complete: it covers scope, filterability, pagination, and the returned fields per row. The only gap is the absence of explicit routing versus the private-leaderboard sibling.

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 description coverage is 100%, so the baseline is 3. The description restates the filter dimensions (language, country, hireable badge, ranking type) that the schema already fully documents, adding no syntax or semantic detail beyond it.

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 ('public leaderboard of the most active coders') plus scope ('over the last 7 days'). The word 'public' implicitly distinguishes it from the sibling wakatime_get_private_leaderboard, so an agent can tell them apart without opening either 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?

Usage is implied by the filters and time window, but there is no explicit when-to-use guidance or routing to alternatives. Notably it never says 'for authenticated/team boards use get_private_leaderboard', which is the obvious alternative a caller would weigh.

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