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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds useful behavioral details: no auth required, case-insensitive search, supported language filtering, and the data source (bestat.statbel.fgov.be). It does not contradict annotations and provides context beyond them.

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, well-structured sentence that front-loads the purpose, then adds filtering, return fields, and usage guidance. It is not overly verbose and includes essential context without padding.

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 listing tool with optional filters and an output schema (though not detailed here), the description covers the return fields, how to chain to datasource_detail, data source, and auth. It does not mention pagination, but limit/offset are in the schema. Overall, it is sufficiently complete for an agent to invoke correctly.

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 covers all 4 parameters with descriptions (limit, locale, offset, search), so baseline is 3. The description reiterates case-insensitive search and language filtering, but adds little new meaning beyond the schema. It does add overall context about the tool's purpose, but not parameter-specific semantics.

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 clearly states the tool browses ~180 raw Statbel datasources, filterable by search and language. It distinguishes itself from siblings by mentioning these are raw datasources backing curated views, and points to statbel.datasource_detail for full metadata, which separates it from the detail tool.

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?

It specifies when to use the tool (browse raw datasources) and directs the agent to datasource_detail for full metadata. It does not explicitly name list_views or view_data as alternatives, but the 'raw vs curated' framing implies the distinction. The guidance is clear enough for selection.

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