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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description's listing behavior is consistent and adds no contradiction. It adds context beyond annotations by revealing the dependency on a prior spill and the environmental requirement for duckdb. It does not detail output shape, but the presence of an output schema lowers the need for that.

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?

Three sentences, each with distinct value: what it lists, when to call it relative to oecd_dataframe_query, and the only environment where it is available. The most actionable statement is front-loaded, and there is no filler.

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 single-parameter read-only metadata tool with a rich schema description and an output schema, the description fully covers what the agent needs: the object being inspected, the prerequisite spill, the ordering relative to the query tool, and the duckdb-only availability. No critical guidance 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?

Schema description coverage is 100%, and the canvas_id schema entry already explains its provenance ('Canvas ID returned by oecd_query_dataset') and referent ('DataCanvas session holding the staged observation tables'). The description reinforces this linkage but adds no new parameter-level meaning, so the baseline score applies.

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 and object: 'List tables and columns staged on a DataCanvas by a prior oecd_query_dataset spill.' It distinguishes itself from sibling oecd_dataframe_query by positioning itself as the pre-query discovery step, so an agent knows exactly what this tool does and which sibling it complements.

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?

Explicitly states when to use it: 'Call this before oecd_dataframe_query to discover exact table and column names for SQL.' It also names the prerequisite (prior oecd_query_dataset spill) and a hard restriction (CANVAS_PROVIDER_TYPE=duckdb), leaving no ambiguity about the invocation context.

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