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

With no annotations, the description carries the full burden of disclosing behavior. It reveals pagination and the ranking rule ('30-day call volume') and recency option, which go beyond what the schema states. It doesn't explicitly mention the return format or read-only nature, but for a listing tool this is adequate.

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?

A single, information-dense sentence that front-loads the action, scope, and key behavior. No filler, no repetition, and every phrase adds value.

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 paginated list with three optional parameters, the description covers the core behavior, sort semantics, and pagination. It does not discuss when to choose sibling tools, but that is a usage-guideline concern. Overall, an agent has enough information to invoke the tool correctly.

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%, so the description must compensate. It explains the meaning of the sort enum values (popular = 30-day call volume, recent = recency) and implicitly covers limit/offset through the term 'Paginated'. The description adds meaningful context beyond raw schema types.

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 uses a specific verb ('listing'), identifies a distinct resource ('every indexed resource'), and distinguishes itself from search_resources by implying a complete enumeration rather than a filtered query. It also conveys the ranking behavior, leaving no ambiguity about what the tool returns.

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 clearly states the context: list all indexed resources with optional sorting. It is easy for an agent to infer when to use this tool versus get_resource (single item) or search_resources (filtered results), but it does not explicitly name alternatives or exclusion conditions, so it falls short of a 5.

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