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

readOnlyHint=true already declares the safe-read profile, so the description correctly focuses on behavior beyond that: it discloses the returned fields (names, sizes, creation dates, expiry status) and the filtering capability. It omits pagination and auth/permission notes, but the return-content disclosure is meaningful because 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?

Front-loaded with the core action, then layered detail in short sentences that each carry weight (owner sourcing, return fields, use cases, filtering). Slightly longer than strictly necessary, but no sentence is 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?

With no output schema, the description compensates by describing the returned fields, and it covers the owner/repo interplay and name filtering. An agent has everything needed to call it correctly and interpret the result.

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 every parameter is already documented in the schema. The description's note that 'repo' accepts 'owner/name' and the owner preference largely restates the schema's own descriptions rather than adding new syntax or semantics, so baseline 3 is appropriate.

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 ('List') and resource ('GitHub Actions artifacts') scoped to a repository, which cleanly separates it from siblings like github_download_artifact and github_list_workflow_runs. The subsequent sentence enumerating return fields and use cases reinforces exactly what the tool produces.

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?

Gives clear when-to-use guidance ('find build outputs like Trivy security scan results, test reports, coverage data') and names github_list_repositories as the source for the owner value. It does not explicitly route to github_download_artifact as the alternative for retrieving content, but the context is strong enough that an agent can place it.

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