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

Annotations already declare readOnlyHint=true, and the description adds useful safety context: Stripe test mode, test cards only, and no real money moves. It also indicates the response contains 'everything the book knows' about the chain, though it does not detail pagination or output shape.

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 short and front-loads the core purpose before adding the test-mode caveat. There is minor redundancy among 'Stripe test mode', 'Test cards only', and 'no real money moves', but the overall length is appropriate.

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 one-parameter read-only lookup by slug, the description covers what the tool returns, how to identify the chain, and the safety environment. It does not describe output fields or error behavior, but the tool is simple enough that these are not critical gaps.

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 schema already provides full coverage of the single `id` parameter with the description 'chain slug'. The description's phrase 'by slug' reinforces this but adds no additional meaning beyond what the schema already states.

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 that the operation retrieves all stored information about a single chain, identified by slug, and the name 'get_chain' reinforces this. It is distinguishable from plural siblings like list_chains, though it does not explicitly name them.

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 phrase 'one chain' implies this is the tool for fetching full details of a single chain, contrasting with list_chains. However, there is no explicit statement about when to prefer this tool over alternatives or when not to use it.

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