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

With no annotations provided, the description carries the full burden, and it does well: it discloses both invocation modes and the contents of the full result ('pieces in order, claim ledger, and reopen conditions'). It does not discuss errors or explicit read-only guarantees, but 'get/list' strongly implies retrieval.

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 with no wasted words. It front-loads the definition and then provides clear, structured usage guidance for both valid call patterns.

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 optional-parameter tool with no output schema, the description is nearly complete: it tells the agent exactly what to expect in both modes and what the full chain contains. It does not cover invalid-chain_id behavior, but that is minor given the 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%, so the baseline is 3. The schema already explains that chain_id comes from the no-argument listing and that omitting it lists all chains. The description adds only minor context about returning 'one chain in full'.

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 identifies the resource ('story chains: multi-piece storylines the desk has covered more than once') and the actions ('list' and 'pass chain_id for one chain in full'). This distinguishes it from sibling tools like get_claim_ledger or get_coverage_record by resource and 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 gives explicit usage instructions: call without arguments to list available chain ids, or pass chain_id to retrieve one chain. It does not explicitly name alternatives or exclusions, but the context is clear enough for an agent to decide how to invoke it.

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