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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and locality are covered. The description adds that lists are curated groupings rather than raw repo search results and that omitting the parameter enumerates everything, but says nothing about the shape or size of the returned data.

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?

Two short sentences that front-load what a list is, followed by the enumeration shortcut. There is mild redundancy with the schema on the omit-slug behavior, but nothing extraneous.

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 one-optional-parameter, read-only lookup with no output schema, the definition covers concept, examples, and the all-lists case. The remaining gap is what a returned list actually contains and how it differs from search_repos results, which is minor but not negligible.

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 single parameter already documents both the slug format and omission behavior. The description restates the omission case, adding minimal meaning beyond what the schema already provides, so the baseline holds.

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 states the resource and its semantics: curated lists that group repos by function and platform, with concrete examples ("self-hosted apps for Linux, AI tools for Windows, MCP servers for macOS"). It doesn't explicitly frame the retrieval verb or contrast with search_repos, but the concept of what a list is, is uniquely defined versus siblings.

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?

Provides one clear conditional: "Leave out slug to see every list", which tells the agent how to enumerate all lists. There is no guidance on when to call this instead of search_repos or find_alternatives, so routing between discovery tools is left to inference.

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