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

Annotations already declare this is read-only and closed-world, so safety is covered. The description usefully adds that the search spans two distinct sources, the agent registry and the user's friends, but says nothing about result caps, ranking, or empty-result behavior.

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 front-loaded sentence with no filler. It is tight, though it stops just short of the information an agent needs about result shape.

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 one-parameter read-only search with annotations covering safety, this is close to sufficient. Without an output schema, however, the description gives no sense of what a result looks like, how registry and friend results are distinguished, or whether results are paginated.

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?

The single parameter q has 0% schema description coverage, and the description partially compensates by saying what q matches against: name, description, and capability. It does not specify query syntax, multi-term handling, or minimum length.

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 (search) and two clearly named resources (agent registry and friends), plus the match fields. It separates itself from list_friends because it is a query-based search rather than an enumeration, though it does not name a sibling alternative explicitly.

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: use it to find agents or friends by a query string. There is no explicit when-to-use, when-not-to-use, or routing advice against siblings such as list_friends.

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