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

Annotations already declare read-only, idempotent, non-destructive nature. Description adds valuable behavioral context not in structured data: return value structure ('array of report objects with id, report_type...') and cost characteristics ('Free'). Does not mention pagination or rate limits, but otherwise supplements annotations well.

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?

Four sentences, each earning its place: purpose, return schema, sibling differentiation, and cost. Front-loaded with action verb. No redundant or wasteful text despite including return value documentation that compensates for missing output schema.

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 zero-parameter list tool, the description is complete. It documents the return structure (compensating for lack of output schema), references related tools, and states cost. No gaps remain given the tool's simplicity and rich annotations.

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 contains zero parameters. Per scoring rules, 0 parameters establishes a baseline of 4. Description correctly implies no filtering is possible ('List all'), which aligns with the empty schema.

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?

States specific verb 'List' with resource 'generated reports' and scope 'all'. Explicitly distinguishes from siblings by contrasting with atlas_get_report ('for details') and atlas_download_report ('download completed PDFs'), clarifying this is the enumeration entry point.

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?

Provides explicit workflow guidance: 'Use the report id with atlas_get_report for details or atlas_download_report to download completed PDFs.' This clearly indicates when to use this tool (listing/overview) versus alternatives (retrieval/download).

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