Discover Fediverse Actor

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

Annotations already declare readOnlyHint:true. The description adds behavioral context by listing return fields (display name, bio, follower/following URLs, inbox/outbox endpoints), confirming it is read-only and informative.

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 three sentences with no filler: first states purpose, second lists returns, third gives input format. Information is front-loaded and every sentence is necessary.

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 lookup tool with one parameter and clear annotations, the description covers purpose, input, and output. It does not mention error handling or limits, but given the tool's simplicity, it is reasonably complete.

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% with a regex pattern and description. The description adds value by explaining the 'handle' concept and showing both '@' and plain formats, which aids agent understanding beyond 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 uses specific verbs ('Find and retrieve the profile') and clearly names the resource ('fediverse user or account', 'actor in ActivityPub'). It distinguishes from siblings like 'discover-instances' by focusing on actors, and provides example handle formats.

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?

The description states when to use (to find any fediverse user) and details the input format with examples. It does not explicitly mention when not to use or alternatives, but for a single-parameter tool, this is sufficiently clear.

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