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

Annotations already declare readOnly, idempotent and non-destructive behavior, so the safety profile is covered. The description adds genuine value beyond that: it names the return content (read and write relays), the underlying kind (10002), and the signer-fallback behavior, which matters because there is no output schema.

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?

Three short sentences with no filler, and the core identity (NIP-65 relay list, kind 10002) is front-loaded before the return values and fallback rule. Every sentence earns its place.

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 single-optional-parameter read tool with no output schema, the description covers identity, return shape, and the parameter default. It is nearly complete; only the relationship to the sibling 'list_relays' is left unaddressed.

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 coverage is 100% and the single parameter is already documented as defaulting to the connected signer. The description restates this default rather than adding syntax or format detail, so the baseline of 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?

States a specific verb and resource with extra precision: 'Get a user's NIP-65 relay list (kind 10002)' and clarifies it returns read and write relays. This is far more informative than the bare name, but it never distinguishes itself from the sibling 'list_relays', leaving the agent to guess which one to pick.

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 supplies a useful conditional: 'If no pubkey provided, uses the connected signer's pubkey,' which tells the agent when the parameter can be omitted. However, it gives no guidance on when to use this tool versus 'list_relays' or 'relay_stats', so the usage context is only implied.

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