list_contacts

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

Without annotations, the description carries the full burden. It does disclose two behavioral traits: read-only and paginated. However, it leaves out how multiple filters combine (AND vs OR), whether matching is exact or partial, and what the response shape looks like, especially given there is no output schema.

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 a single front-loaded sentence with no filler. It states the core purpose and searchable fields first, then adds the cross-tool dependency and read-only flag. Every word 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 six-parameter read-only search with no output schema, the description provides essential details: search criteria, pagination, read-only nature, and the tag_ns source. However, it omits filter combination behavior, return value format, and any guidance on when to choose this over find_contact or get_contact, leaving some important gaps.

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 adds meaning by listing the searchable fields and explicitly noting that tag_ns comes from list_tags. But it does not explain page/limit semantics, filter interactions, or the meaning of null values.

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 identifies a specific verb ('Search'), a resource ('contacts'), and the searchable attributes (phone, name, email, tag_ns). It is clear and unambiguous, but it does not explicitly distinguish itself from sibling tools like find_contact or get_contact, so it misses the top score.

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?

There is no guidance on when to use this tool versus alternatives such as find_contact or get_contact. The only usage hint is that tag_ns comes from list_tags, which is a prerequisite rather than a decision rule.

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