list_chains

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

Without annotations, the description carries the full burden of behavioral disclosure. It adds useful context about `isDefault` and `DEFAULT_CHAIN_ID` env resolution, but it does not mention potential errors, rate limits, or the exact structure of the returned list beyond slugs. For a read-only listing operation, this is acceptable but not fully comprehensive.

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 concise—two sentences—and front-loaded with the primary purpose. The second sentence adds crucial usage context without redundancy. Every word contributes to the tool'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?

Given the tool's simplicity (no params, no output schema), the description covers the essential aspects: what the tool lists, how to use the results, and what `isDefault` means. It could be more explicit about the return format (e.g., array of objects), but the description is sufficient for an agent to know when and how to invoke this tool.

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 has zero parameters, so the baseline is 4. The description adds meaning beyond the empty schema by explaining that the returned `chain` slugs are used as arguments in other tools and that `isDefault` indicates the fallback chain. This enriches the conceptual understanding of how the tool's output is consumed.

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 clearly states the tool 'lists the chains this server is configured for', using a specific verb and resource. It distinguishes this tool from siblings (ping, resolve_agent, etc.) by focusing on chain configuration. The added detail about `isDefault` and the relationship to other tools' `chain` argument further clarifies its unique purpose.

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 provides explicit context that this tool must be used to obtain valid `chain` slugs for other tools, stating 'Every other tool's `chain` argument must be one of the `chain` slugs returned here'. It implies the appropriate time to use this tool (before using other tools with chain arguments), though it does not explicitly mention when not to use it or name alternatives.

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