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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds two things beyond that: the tool is 'Free' (no credit cost, meaningful given the paid atlas_buy_pack sibling) and the content shape of the response. It goes modestly beyond structured data without contradicting it.

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 tight sentences plus the one-word cost note 'Free'. The resource description is front-loaded and nothing is redundant or padded; every clause earns its place.

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 input parameters, no output schema and rich annotations, the description carries the remaining burden by stating what the returned records contain (models, character caps, requirements) and how the ids are reused. Nothing an agent needs to call this correctly 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?

The tool takes zero parameters, so the baseline is 4 per the rubric. The description still usefully clarifies that a 'target id' is the value this tool yields and that other tools consume, which gives the otherwise-absent parameter concept meaning.

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 specifically what the tool returns: the target models the atlas knows, each with its prompt-field character cap and requirements. It is clearly a catalog/lookup resource distinct from the action-oriented siblings (atlas_draft, atlas_lint, atlas_kit), though the phrasing is nominal rather than a verb+resource claim.

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?

'Pass a target id to atlas_kit, atlas_draft and atlas_lint' explains the downstream role of the returned ids, which effectively tells the agent when to call this first. It gives clear context but no explicit when-not condition or exclusion relative to other lookup siblings such as atlas_show or atlas_search.

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