Connect Spotify

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

Annotations only declare safety hints (non-read-only, idempotent, open-world, non-destructive), while the description adds the genuinely non-obvious behavior: the call is async and returns a login URL rather than completing auth, a follow-up status call is required, force is needed on ~6-month token expiry, and the tool is blocked during draft construction. That is substantial disclosure beyond the annotations.

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?

Dense, front-loaded sentences ordered as action, follow-up, optional params, edge case. No filler; every clause carries operational information.

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?

With no output schema, the description still tells the agent what is returned (a login URL) and what to do next (call status), plus the refusal condition. Nothing needed to invoke the tool correctly is missing.

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 50%: clientId is documented in the schema, but force has none. The description fully compensates by explaining force's purpose (switch accounts / re-login) and adds the combining benefit of clientId ('saved before the login starts, no separate setup'), though the clientId format detail is already in the schema.

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+resource ('Start the Spotify login') and immediately clarifies the exact mechanism ('Opens the browser and returns the login URL immediately'). This distinguishes it from siblings like status (which confirms) and disconnect, so an agent can pick correctly without opening schemas.

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?

Explicitly routes the agent: call this to start, then call status to confirm; pass clientId to avoid separate setup; pass force:true to switch accounts/re-login every 6 months. It also states a when-not condition ('Refused while a draft is building'), leaving nothing to inference.

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