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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds genuinely useful context on top: an auth requirement (League role, Read scope), the fact that results are paged, and the default value of include_sessions. It stops short of describing page-size limits or the full return envelope, but the behavioral picture is solid for a read tool.

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?

Three short, front-loaded sentences with zero filler: payload shape first, then pagination, then the permission/endpoint constraint. Every clause carries information an agent can act on.

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 carries the burden of return-shape disclosure and does so partially (sessions contain id and name), but it never says what fields a league object itself has or how pagination metadata is surfaced. For a simple read-only list tool with 100% schema coverage and annotations, this is nearly 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%, so the baseline is 3, and the description earns a step above it by clarifying the default state of include_sessions and disclosing that sessions come back as only id and name. It adds no detail on page/page_size/league_id beyond what the schema already states.

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 specific resource (the club's leagues) and what comes with it (sessions with id and name when include_sessions is true), plus the endpoint GET /api/v1/league/get. It does not explicitly distinguish itself from the sibling courtreserve_list_league_sessions, so an agent must infer the boundary from the include_sessions clause.

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?

"Needs the League role (Read)" is a real prerequisite that tells the agent when the call will fail, and the include_sessions note implies when to prefer the sessions-expanded variant. But there is no explicit when-to-use / when-not-to-use guidance nor a named alternative for agents who want session detail without league overhead.

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