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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety and scope profile is covered. The description contributes real value beyond that by disclosing the result contents (page URLs and API endpoints) and that archived as well as current basho are included, but it does not mention ordering, completeness, or pagination behavior.

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 adds no filler. The phrase 'available in o-sumo' is mildly redundant with the surrounding domain but usefully ties the tool to its data source.

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 zero-parameter read-only list with no output schema, the description is nearly sufficient: it names the scope (current and archived) and the returned fields. It could go one step further by noting whether the returned entries include the identifiers other sumo tools consume.

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?

The tool takes zero parameters, so the baseline is 4. The description correctly implies no filtering or scoping options are available, leaving nothing for the schema to explain.

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 gives a specific verb ('List') and resource ('current and archived Grand Sumo basho available in o-sumo') and even states what each entry carries (page URLs and API endpoints). The resource is clearly distinct from the siblings (banzuke, rikishi profiles, torikumi), though it never names them explicitly.

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?

There is no explicit when-to-use guidance, no mention that this is the natural entry point for discovering the basho identifiers the other sumo tools likely require, and no stated exclusions. The usage is only implied by the listing nature of the tool.

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