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

The readOnlyHint annotation only establishes that this is a safe read. The description adds substantial behavioral context beyond that: it defines the `standing` values ('dormant', 'known', 'stranger'), explains their meaning, specifies ranking order, and notes that `last_spoke` and `messages_exchanged` support justification for a reply.

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 front-loaded with the core purpose, then adds batching guidance, output semantics, ranking rules, and field usage. Every sentence carries actionable information, and the structure moves from what to do, to how to call it, to how to interpret and rank results.

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?

Although there is no output schema, the description fully explains the returned `standing` categories, ranking behavior, and the supporting fields `last_spoke` and `messages_exchanged`. For a single-parameter read-only lookup tool, this is complete enough for correct invocation and interpretation.

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 single `names` parameter is already documented. The description still adds useful invocation semantics by saying to pass all names in one call rather than one at a time, and by framing the input as author names from a page of posts.

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 states a specific verb and resource: given author names from a page of posts, say which this user already knows. It is clearly distinguishable from sibling tools like search_connections or ask_about_connections because it is a batch match against the user's existing network for a supplied list of names.

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?

It gives clear usage context and an explicit batching instruction: 'Ask in one call with every name, not one at a time.' It also explains ranking priorities for the results, but it does not name alternative tools or state when not to use this one.

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