list_contacts

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, and the description adds genuinely new behavior: results are cursor-paginated (not offset), ordered newest first, and multiple filters intersect via AND. Gaps remain around auth/scope requirements and the response envelope, but for a read-only list tool this is solid added context.

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 short sentences, front-loaded with purpose, then pagination/ordering, then filter semantics. Nothing is redundant and no sentence needs a second read.

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?

With nine all-optional parameters, the description correctly focuses on the two things the schema cannot express: result ordering/pagination and AND-combination of filters. The main remaining gap is return-shape disclosure (no output schema, so the contact object structure and next_cursor field are never described), and it does not state what an unfiltered call returns.

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 coverage is 100%, so the baseline is 3, and the description earns an extra point by documenting the cross-parameter combining rule ('Filters combine with AND'), which no individual schema property conveys. It does not restate the per-field matching semantics (exact vs substring), but those are already covered by 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 opens with a specific verb+resource ('List contacts'), which cleanly separates it from get_contact, upsert_contact, and update_contact in the sibling set. It does not explicitly name the read-one alternative, so it falls short of the top mark, but an agent can place it correctly.

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?

Usage is only implied: the mention of filters and cursor pagination signals 'use this to browse/filter a contact collection,' but nothing states when to prefer get_contact for a single record or that all filters are optional. No exclusions or prerequisites are given.

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