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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds useful behavioral detail by enumerating the response contents, which is valuable since no output schema is present. It does not cover error or not-found behavior, but for a simple lookup this is a minor gap.

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 sentence that front-loads the action and ID format, then efficiently lists return fields. Every part adds value, and there is no redundancy or 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 one-parameter, read-only lookup tool with no output schema, the description is complete: it states the source, the ID format, and the full set of returned information. No critical details are missing for an agent to correctly invoke it.

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 schema already fully documents the single cwe_id parameter with an example, and the description supplements this by explicitly defining the accepted formats: 'CWE-NNN or NNN'. This added format guidance goes beyond the schema's example value.

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 identifies the tool as a MITRE CWE detail lookup by ID and lists the specific fields returned (name, abstraction, status, description, parent/child relationships). It also distinguishes itself from CVE-related sibling tools by specifying CWE and the accepted ID format.

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 provides clear context that this tool is for retrieving CWE details when a CWE ID is available, and even specifies the accepted ID format. It does not explicitly mention alternatives or exclusions, but the 'by ID' framing makes the usage context clear.

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