Complete SoundCloud login manually

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

Annotations already signal readOnly=false and destructive=false, so the mutation profile is covered. The description adds helpful context about the manual fallback scenario and acceptable input forms, but it does not disclose whether completing a login replaces an existing session or what happens on failure.

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?

Two sentences with no filler. The purpose and trigger condition are front-loaded, followed by the input format guidance. 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 one-parameter auth completion tool, the description covers the trigger condition, the relationship to auth_login, and both acceptable input formats. It does not describe return values, but since no output schema exists and invocation does not depend on return values, this is a minor gap; a note about verifying success via auth_status could improve it further.

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 describes the single parameter completely at 100% coverage, including the redirect URL and bare authorization code options. The description restates this in plainer terms but adds no meaningful new semantic information beyond 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?

The description states a specific action and resource: 'Finish a login started with soundcloud_auth_login'. It clearly distinguishes itself from the sibling auth tools by explaining that this is the manual fallback completion step.

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 explicitly states when to use the tool: when the browser callback could not reach the local listener. It names soundcloud_auth_login as the companion tool, giving the agent a clear decision rule and differentiating this from auth_status, auth_switch, and logout.

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