Registered repositories

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

With no annotations present, the description carries the full burden. It discloses an important behavioral trait: roots are never exposed. However, it does not explicitly state whether the operation is read-only, what the output format is beyond IDs, or whether any authorization is required.

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 two short sentences with no filler. The core purpose is front-loaded, and the usage hint follows immediately. Every word contributes to the agent's understanding.

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 parameterless list tool with no output schema, the description communicates the essential behavior: return repository IDs and avoid exposing roots. The 'call this first' guidance completes the practical context, though the exact response shape is implied rather than explicit.

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?

This tool has zero parameters, so there is no parameter semantics to convey. The baseline for a zero-parameter tool is 4, and the description adds no contradictory or confusing parameter-related information.

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 a specific verb ('List') and resource ('registered repository IDs'), and the word 'only' sharpens the scope. This clearly distinguishes it from the sibling tools, which operate on repository contents rather than just enumerating IDs.

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 instruction 'Call this first' gives explicit sequencing guidance, and 'roots are never exposed' warns the agent about a limitation. It does not name sibling alternatives explicitly, but the first-step positioning plus the ID-only scope makes the usage context reasonably clear.

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