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

Annotations already indicate read-only, idempotent, and non-destructive behavior, so the bar is lower. The description adds context about the source (data.govt.nz CKAN) and the returned metadata fields, which is useful. However, it doesn't disclose other behavior such as error handling, authentication requirements, or rate limits, which would be additional value.

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 source and then specifies the exact resource and fields. It contains no fluff and earns its place.

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 simple single-parameter read-only tool with an output schema and strong annotations, the description covers the source, purpose, and parameter semantics. It is complete; the output schema handles return values, and annotations handle safety.

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 0%, but the description compensates by explicitly stating 'by resource ID,' which clarifies the meaning of the single 'id' parameter beyond its name. The example in the schema reinforces this. Without a full schema description, this is sufficient.

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 retrieves metadata for a single resource by resource ID, listing specific fields (URL, format, size, description, last modified). It distinguishes itself from sibling tools by specifying 'resource' rather than package, group, or organization, making its purpose unambiguous.

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 implies usage: if you need metadata for a specific resource ID, use this tool. It doesn't explicitly mention alternatives (like package_show for datasets) or state when not to use it, so it lacks the explicit exclusions needed for a 5. However, the context is clear enough for most cases.

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