List Contacts

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

Annotations already declare readOnlyHint, destructiveHint, and idempotentHint. The description adds caching behavior (20 min fresh, 2 hours stale) and the force_refresh parameter, which provides additional behavioral context beyond the annotations.

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 well-structured with an emoji, clear sections for output, caching, arguments, and returns. Every sentence is informative and necessary, with no wasted words.

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?

Given the tool's complexity (4 parameters, many siblings, output schema exists), the description covers safety, caching, parameter details, and return fields. It is sufficiently complete for effective use.

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 fully compensates by explaining each parameter in detail: account_id, limit (with range), use_cache, and force_refresh. It clarifies defaults and caching logic, adding significant meaning beyond the 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?

The description clearly states the tool's purpose: '📖 List contacts (read-only, safe for unsupervised use)'. It specifies what it returns ('names, email addresses, and phone numbers'), distinguishing it from siblings like search_contacts and contact_get.

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?

While the description indicates the tool is read-only and safe, it does not explicitly guide when to use this tool versus alternatives (e.g., search_contacts for searching, contact_get for a single contact). The caching advice is helpful but does not address usage context.

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