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

Annotations already declare readOnly, openWorld, idempotent, non-destructive; the description adds valuable context beyond them: the 200-result cap, the underlying source (sdmx.oecd.org), and the fact no auth is required. This is enough for safe invocation without needing pagination details.

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 sentences carry all essential information with no filler: action, scope, filtering options, result cap, downstream integration, source, and auth requirement. The most decision-relevant facts are front-loaded.

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 reference/discovery tool with 100% schema coverage, an output schema, and strong read-only annotations, the description covers what the tool does, its constraints, and the next steps an agent should take. Nothing critical for correct invocation is missing.

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?

Input schema covers both parameters with descriptive explanations and examples, so the baseline is 3. The description adds a little semantic framing by mapping query to 'name/id' and agency_id to 'directorate', but it largely repeats what the schema already documents.

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?

Description opens with a specific verb-resource pair, 'Search or list OECD statistical dataflows', and immediately sets scope: ~1500 official series across all OECD directorates. It distinguishes itself from the downstream data-retrieval siblings by instructing that returned agency_id + dataflow_id feed oecd-data.structure and oecd-data.data.

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 gives clear use contexts: filter by query for name/id, filter by agency_id for directorate, or omit both to list all with a 200-result cap. It also routes the agent to the next appropriate tools (oecd-data.structure and oecd-data.data), though it doesn't explicitly state when not to use this tool relative to sibling reference tools.

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