Finish a sign-in with the callback URL

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

Annotations already declare that this writes state (readOnlyHint=false) and reaches an external service (openWorldHint=true), so the safety profile is covered. The description usefully frames the tool as an OAuth recovery path rather than a primary sign-in, but says nothing about code/state expiry, failure modes, or what happens to an already-connected account.

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, front-loaded with the action, followed by the disambiguating usage condition. No restated boilerplate and nothing extraneous to trim.

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 tool with annotations and no output schema, the definition covers what to supply and when. It stops short of describing the outcome (e.g. account now listed by list_accounts) or what an invalid/expired callback URL produces, which would fully close the loop.

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%, so the baseline is 3, but the description adds real meaning by noting the URL 'contains ?code=...&state=...', signalling that the query string must be preserved intact and not truncated. That goes beyond the schema's 'full address-bar URL after approving, starting with http'.

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 ('Finish a connect_account sign-in') and ties it to a concrete input ('the full URL the browser landed on after approving'), naming the sibling connect_account whose flow it completes. An agent can distinguish it from connect_account and auth_status without opening any schema.

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 explicit trigger conditions: the callback page did not load, or sign-in happened on another device. That is a clear when-to-use, though it does not explicitly state that a normal flow should just use connect_account's own callback, leaving the alternative implied by naming connect_account.

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