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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered by structured data. The description adds genuinely useful non-schema context — that the algorithm is deterministic and that each call costs 1 credit — but says nothing about return shape or handling of non-numeric input.

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 short sentences, front-loaded with the operation and its result order, with the cost note appended cleanly. "using a deterministic sorting algorithm" is mild filler but does carry the idempotence/determinism signal, so it roughly 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?

For a trivial single-parameter read-only utility with full schema coverage and annotations covering safety and idempotence, the description supplies everything needed to call it correctly. Only the input-format ambiguity and return format are unaddressed, and no output schema exists to offset that.

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 the single parameter is fully documented in the schema, so the baseline is 3. The description reinforces that the input is numeric values to be ordered ascending, but does not clarify the anyOf ambiguity (array of strings vs. a single string) that the schema leaves open.

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 a specific verb and resource ("Sorts a list of numbers") plus the resulting order (ascending), so the operation is unambiguous. It does not distinguish itself from adjacent list/ordering tools such as merge_sorted_lists or find_n_largest, which is the only thing keeping it from a 5.

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?

Usage is only implied by the noun phrase "list of numbers"; there is no explicit statement of when to prefer this over sibling tools like merge_sorted_lists or find_n_largest, and no preconditions are given. Adequate for an obviously-scoped utility, but no routing guidance.

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