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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds modest context — default of 5, hard cap of 10, and inclusion of page URLs — but says nothing about freshness of 'current' runs or what happens when a league has no qualifying clubs.

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 sentence, front-loaded with purpose, then the kind enumeration, count bound, return shape, and the resolve dependency. No filler.

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 three-parameter read-only query with rich annotations and no output schema, the description covers what is returned and the one input an agent cannot guess (league slug provenance). Slightly incomplete on edge-case behavior but adequate to call 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 description coverage is 0%, so the description must carry parameter meaning; it partially does by explaining that league is a slug obtained from resolve, while kind and n are only restated from the schema (enum values and 1-10/default 5 are already structured). The league slug format itself is not elaborated beyond its source.

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 — 'Returns the clubs of one league with the longest current run' — and enumerates the four kinds, the count range, and the per-club page URL. The scope 'of one league' implicitly separates it from the per-club club_runs sibling.

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?

'Takes the league slug from resolve' gives a clear prerequisite and names the sibling tool that supplies the required parameter. It stops short of stating when to prefer this over club_runs or league_strength, so there are no explicit exclusions.

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