List contacts

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

Annotations already disclose read-only, idempotent, non-destructive behavior. The description adds no behavioral details beyond listing/searching, and does not mention pagination, archived handling, or open-world result semantics. This is acceptable given the annotations but not rich.

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?

One sentence front-loads the tool's purpose and then explains the two search modes. There is no fluff; every clause earns its place.

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 list tool with strong annotations and a fairly detailed schema, the description plus schema cover the main parameters well. The only minor gap is include_archived, which has no schema description and is not addressed in the description, though its name is self-explanatory.

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 high (83%), and the description enriches the query parameter by listing the specific fields searched (name, email, phone, customer id, tax number, address) and characterizes filter as structured narrowing. This adds meaning beyond the bare schema text.

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 a specific action ('List or search') and resource ('contacts') and clarifies the scope as customers and suppliers. This is clear but does not explicitly distinguish itself from the sibling get_contact, so it falls just short of full sibling differentiation.

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 clear guidance on when to use query (free-text search across specified fields) vs filter (structured narrowing). It does not explicitly state when to prefer list_contacts over get_contact or other sibling tools, but the general usage context is clear.

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