Spotify Login

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

With no annotations, the description carries the full burden and does substantial work: it discloses that the tool is interactive (asks the user to quit the browser with Cmd+Q), that it blocks and polls until capture, and that it writes the session to the filesystem so later runs skip the browser. That persistence side effect and the user-interruption requirement are exactly the traits an agent needs. It stops short of saying what happens if the timeout elapses or the capture fails, and doesn't state that the user must already be logged in to Spotify in the browser.

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 core purpose is front-loaded in a single short sentence, with mechanics following. The second sentence is long and clause-heavy but each clause (fallback order, Cmd+Q flush, polling, persistence) conveys distinct operational information, so little is wasted.

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 an interactive, filesystem-writing tool with no annotations and an output schema already present, the description covers the important unknowns: interactivity, blocking/polling, and persistent storage. The notable remaining gap is failure behavior on timeout and the precondition that the browser must be logged into Spotify.

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 browser and timeout parameters are already documented in the schema. The description only implicitly touches timeout ('keeps polling until the session is captured') and adds nothing about the browser values or what happens when the wait expires, so it does not meaningfully exceed the schema baseline.

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 ('Capture a working Spotify session') and immediately scopes the prerequisite ('free account is enough'). The described fallback chain (stored session, then browser profile) makes it unmistakably distinct from sibling tools like spotify_session_status or spotify_logout, which inspect or destroy rather than capture a session.

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 explains the internal order of attempts and the interactive escalation path, which implies when this tool is needed (no usable stored session yet). However, it never states when to call this versus spotify_session_status or what to do if a session already exists, leaving the selection decision to inference.

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