contacts_search

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds that the search is scoped to a single channel, which is genuine behavioral context, but it says nothing about match semantics (partial vs exact, case sensitivity) or result limits/pagination, which matter for a search tool.

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?

A single compact sentence with the purpose front-loaded and transport details (REST path, gRPC method, socket name) relegated to a parenthetical. Nothing is wasted, though the transport metadata is arguably noise for an agent deciding whether to call the tool.

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 simple read-only lookup with no output schema, the definition is minimally sufficient: it conveys what is searched and in what scope. It falls short on result behavior (pagination, limit semantics, empty-result handling), which an agent would need to call it well.

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 carries the burden. It clarifies that the query matches 'name or number' and that results are confined to one channel (implying channelId), which adds real meaning. The 'limit' parameter is left entirely unexplained in both the schema and the description.

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 verb+resource+scope: 'Search a channel's contacts by name or number', which distinguishes it from contacts_list (enumerate all) and contacts_get (fetch one). It does not explicitly name those siblings, but the matching criteria make the distinction inferable.

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 implied by 'search by name or number' – an agent can infer this is for lookup rather than enumeration. However, there is no explicit statement of when to prefer this over contacts_list or contacts_get, and no prerequisites or exclusions are given.

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