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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false), so the lower bar applies. The description adds genuinely useful behavior beyond that: it returns the full set by default, English is the default language, and passing codeset narrows the response to one set. It does not mention rate limits or response size, which is a minor gap.

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 identity of the resource in the first clause and puts the actionable 'Use this to...' guidance second. The long enumeration of code sets is dense but each item carries real information (counts, meanings), so it earns its length; a tighter edit could still trim the mid-sentence list.

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?

No output schema exists, so the description must hint at the return shape — it does, stating the full set is returned by default and can be narrowed per set. Combined with the safety annotations and fully documented schema, an agent has what it needs; only the actual field structure of each code set goes unstated.

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 the schema already documents both parameters and all ten enum values, establishing the baseline of 3. The description reinforces this ('English by default; pass codeset to fetch just one') and the enumerated code-set list gives real-world scale, but it adds nothing the schema lacks — notably no fr/en equivalence detail.

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 and resource — StatCan reference code sets (WDS getCodeSets) — and immediately distinguishes itself from the rest of the statcan_* siblings, which deal in cube data, metadata, series and vectors rather than lookup tables. An agent can tell what this returns without opening any 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?

Gives two concrete triggers: decode a frequencyCode/scalarFactorCode/statusCode/uomCode/subjectCode seen elsewhere in the pack's output, or browse the subject/survey taxonomy. That is strong when-to-use guidance, but it names no alternative tool and states no when-not condition, so it stops short of the top band.

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