list_contacts

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

With no annotations provided, the description carries the behavioral disclosure burden. It goes beyond a simple 'list' by revealing the return structure ({items, count, hasMore}) and pagination semantics. It doesn't mention auth or rate limits, but for a read-only list tool, the information given is sufficient and adds meaningful 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?

Three sentences, each earning its place: purpose, pagination behavior, and alternatives. Front-loaded with the main action, no redundancy or filler. The structure is compact yet comprehensive.

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 paginated list tool with no output schema, the description covers the essential aspects: what is returned, how pagination works, and how it relates to sibling tools. It is complete enough for an agent to invoke and interpret results without additional documentation.

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 documents both parameters with descriptions and defaults (100% coverage), so the baseline is 3. The description adds extra value by explaining the pagination relationship between offset and limit in the context of hasMore, which is not in the schema. This elevates the parameter understanding beyond raw field definitions.

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 begins with a specific verb and resource ('List contact summaries from Outlook') and clearly distinguishes from siblings by pointing to get_contact for full details and search_contacts for name-based search. This makes the tool's unique role 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?

It explicitly states when to use alternatives: 'For full details... use get_contact' and 'Use search_contacts to find contacts by name.' It also gives pagination usage guidance, telling how to increment offset when hasMore is true, providing clear context for when this tool is appropriate.

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