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

Annotations already declare readOnly=true, idempotent=true and openWorld=true, so the safety profile is covered. The description adds genuinely non-obvious behavior: only the first two sub-collections are fetched, and container images/software/guide code carry licenses distinct from the CC0 data. Return details are left to the output schema, which is acceptable.

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-loads the purpose before a colon-delimited inventory of components, so structure is strong and each clause carries information. The licensing sentence is slightly tangential and the run-on list is dense, but nothing is wasted.

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 an aggregate read tool with a rich input schema and an existing output schema, the description need not explain return values, and it correctly leaves them to the schema while describing scope. The only minor gap is the lack of guidance on the sibling aggregate calls, but the essentials for invoking it correctly are present.

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?

Single parameter with 100% schema description coverage; the schema already documents the recid formats, prefixes, and where to obtain it. The description adds nothing about recid semantics, so the baseline 3 applies.

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 (Assemble) and a precise resource (analysis environment for a record) and then enumerates the exact artifacts returned: container images, CMSSW release/global tag, condition-data/VM/validated-run records, example software, quoted guide sections. This clearly distinguishes it from siblings, and it even routes the file-listing case elsewhere.

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?

Names an explicit alternative ('Use cern_opendata_list_files for the record's files') with the condition that selects it, which is real routing guidance. However, it does not clarify when to prefer get_records or get_validated_runs (broadly overlapping siblings) over this aggregate call, so it stops short of full when-to-use/when-not coverage.

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