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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=false, so the safety profile is partly covered. The description still adds non-obvious behavioral constraints: it refuses nsec input, and it warns that connection secrets must not be placed in chat, which shapes how an agent should route the user.

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, front-loaded sentences, each carrying distinct information (precondition, preferred alternative, input rejection). No filler, no repetition of the tool name.

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 state-changing connection tool with no output schema, the description covers the critical when/when-not and input-security concerns. It omits what happens after a successful connect (persistence, follow-up with get_signer_status or disconnect_signer), which would help an agent plan the next step.

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 0% for the single required parameter, so the description has to compensate. It does so by naming the accepted format ('bunker:// URI') and stating a hard negative constraint ('Never accepts an nsec'), which is more than the bare 'string' in the schema conveys; the 8192 max length remains undocumented.

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 ('Connect a bunker:// URI'), so the agent knows exactly what happens. It does not explicitly name the sibling it differs from (e.g. begin_nostrconnect_pairing, get_setup_url), but the URI-type specificity makes it reasonably distinguishable from surrounding signer tools.

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?

Gives an explicit precondition ('only when the user knowingly supplied it') and an explicit preferred alternative (the local setup page) with a rationale. This is exactly the when-to-use / when-to-prefer-something-else guidance the dimension asks for.

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