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

Beyond the readOnly/idempotent/destructive annotations, the description discloses two behavioral facts: the return payload (total count plus the combinations) and the hard 5000-result truncation. The truncation is important operational context an agent would otherwise only discover at runtime.

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?

Three tight sentences with the purpose front-loaded and the truncation note placed second. The source URL is minor extra provenance, but it is a single short clause that does not bloat the description.

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 a two-parameter tool with full schema coverage, an output schema, and safety annotations, this description covers the essentials. The only unstated edge cases are behaviors like choose exceeding the item count, which the schema bounds and mathematical definition make largely predictable.

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%, with both items and choose already documented in the schema itself. The description adds only a modest explicit link between 'r' and the choose parameter and 'list' and items, but it does not carry the parameter-documentation burden.

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 names a specific verb ('List') and resource ('every way to choose r items from a list'), and clarifies the combinatorics semantics with 'ignoring order (combinations)'. This clearly distinguishes it from the many sibling generator tools and other list-processing tools.

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 use case is clear from the first sentence: use this whenever you need to enumerate all order-insensitive selections of r items. It does not name alternatives or state when not to use it, though no sibling tool competes for the same task (e.g., random_team_generator selects a random subset, not all combinations).

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