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

readOnlyHint=true already establishes the safe-read profile, and the description adds meaningful behavioral context beyond that: odds follow 'standard CS2 tier weights' and are 'renormalised over the tiers actually present.' That explains how the derived numbers are computed, which an agent could not infer from annotations. It stops short of disclosing pagination behavior or return shape.

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 sentences, zero waste, and front-loaded: the primary list behavior leads, the single-container mode follows, and the odds caveat is tacked on last where it belongs. Every clause carries information.

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 usefully states what comes back (contents, drop odds, expected opening value) and how the odds are derived. For a read-only browse tool whose parameters are fully schema-documented, this is nearly complete, though it omits any note on result volume or pagination defaults.

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 description coverage is 100%, so all six parameters are already documented in the schema. The description restates the slug behavior (single container instead of list) and adds the odds-renormalisation note, but adds no syntax or format meaning beyond the schema. 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+resource ('List Counter-Strike 2 cases, capsules and souvenir packages') and a distinct secondary mode (get one container with contents, drop odds, and expected opening value). The resource is clearly differentiated from siblings like browse_collections, search_skins, and get_case_roi_ranking, so an agent can tell it apart without opening the 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?

The description makes the two operating modes explicit: list containers, or fetch a single container by slug ('or get one container with its contents'). It gives clear context for when each mode applies but does not name alternatives (e.g. get_case_roi_ranking, browse_collections) or state exclusions, so it falls just short of a 5.

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