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

Annotations only declare readOnlyHint, so the description does the heavy lifting: it discloses the manifest field set, that retention-swept files appear as 'removed' with bytes gone, and that output may be truncated. Auth requirements and rate limits are not covered, but for a read-only listing this is strong disclosure.

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 and the return shape, with no filler sentences. The semicolon-chained field list is dense but each clause carries real information, so it reads as compact rather than bloated.

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 enumerating the manifest fields (path, bytes, stage, sha256, removed, truncated, source) and the caveat on deleted files. Nothing an agent needs to interpret or correctly call this tool is missing.

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 there is a single required run_id, so the schema already carries the semantics. The description only references 'a run's' artifacts and adds no format or id-syntax detail beyond that.

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 ('List a run's collected artifacts as a typed manifest') and immediately distinguishes itself from the sibling that returns file contents. An agent can separate this from mcg_get_artifact without opening either schema.

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?

Explicitly states when not to use it ('Never returns file contents') and names the alternative ('fetch one file with mcg_get_artifact'), plus a second exclusion ('removed ... do not fetch it'). Routing conditions are fully specified.

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