Contributor Lookup

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It indicates the operation is a read/lookup by saying 'look up' and 'queries', and it reveals that two external systems are contacted. However, it does not explicitly state that the operation has no side effects, nor does it mention potential external dependencies like GitHub rate limits or network failures.

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 sentences long with no filler. The first sentence front-loads the core purpose, and the second adds essential detail about the two query targets. Every sentence earns its place, making this highly concise and well-structured.

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?

The tool is simple (one parameter, output schema present), so the description is nearly complete: it names the input, the two sources, and the two outputs. The only gaps are the absence of explicit usage boundaries and external caveats, which are minor given the availability of the output schema and low complexity.

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 description coverage is 100%, and the schema already documents the username parameter with examples. The description adds the semantic link that the username corresponds to a GitHub contributor and that it is used to fetch balance and merges, but it does not add meaning beyond what the schema already provides. Thus the baseline 3 is appropriate.

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 clear action ('Look up a contributor's RTC balance and merge history') and explicitly names the two data sources queried: the RustChain network for wallet balance and GitHub for merged pull requests. This is a specific verb+resource statement that clearly distinguishes it from siblings like rustchain_balance, which likely only handles balances. No ambiguity or tautology.

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 implies the tool should be used when a contributor's combined balance and merge history is needed, but it never explicitly states when to prefer this over alternatives like rustchain_balance or bounty_search. There is no explicit when-not-to-use guidance or mention of alternatives, leaving the agent to infer the boundary between tools.

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