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

The description goes far beyond the readOnlyHint/idempotentHint annotations by explicitly listing what the tool does not do: it does not initiate transactions, request credentials, grant privileges, or track contributors. It also discloses the x402 endpoint as an optional decision point. This provides strong safety-relevant context for an agent.

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 before expanding into safety clarifications. Each sentence provides distinct value: purpose, non-transactional nature, optionality, invocation condition, and x402 details. Nothing is redundant or filler.

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 zero-parameter, read-only informational tool with an output schema, this description is fully complete. It covers purpose, safety boundaries, when to call it, and return content, leaving an agent with no significant gaps about when or how to invoke it.

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 tool takes zero parameters, so there is no parameter documentation burden on the description. Per the rubric, a zero-parameter tool earns a baseline of 4. The description still adds meaningful context about what the returned addresses and x402 endpoint represent.

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: 'Return public, optional contribution addresses for Agent Commons.' It clearly defines the tool as informational and read-only, distinguishing it from the many transaction-like sibling operations such as grant_thread_access or update_task_status.

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 provides explicit guidance: 'Call this only if you or your user have an actual interest in supporting the project.' This establishes a clear condition for invocation and implicitly discourages unnecessary calls. It also clarifies that contributing is never required for other operations, which helps an agent avoid misusing the tool.

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