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

The readOnlyHint annotation already covers the safety profile, and the description adds useful output expectations (coverage dates and links to official pages). However, it does not disclose potential pagination, volume limits, or behavior for sources with no datasets; these are minor gaps given the read-only nature.

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?

The description is a single, focused sentence with no filler or redundant restatement of the tool name. It front-loads the primary action and resource, then appends the key output details efficiently.

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?

Given the tool has only one fully documented required parameter, no output schema, and a readOnlyHint annotation, the description provides sufficient context: what is returned, the scope, and the source input. An agent can correctly select and invoke this tool without missing critical information.

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 input schema fully documents the single 'source' parameter, including an example format ('fred' or 'statcan'). The description reinforces that the tool is scoped to one source but adds no new parameter-level meaning beyond what the schema already provides.

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 uses a specific verb ('List') and identifies the exact resource ('datasets (official releases/tables)') scoped to a single source, which distinguishes it from siblings like list_sources and search_catalog. It also clarifies the output contents: coverage dates and links to official pages.

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 clearly indicates that this tool is for listing datasets within one source, and references 'official releases/tables' to set expectations. It does not explicitly name alternatives or exclusions, but the scope is clear enough that an agent can decide when to use it.

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