start_auth

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

The description discloses that the tool returns a URL that the user must visit, which is key behavioral information. Annotations provide readOnlyHint=true, lowering the bar for transparency, but starting an OAuth flow typically involves server-side state changes (e.g., generating a request token), which is not mentioned. This creates a mild inconsistency but does not outright contradict.

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 description is exceptionally concise, consisting of two sentences that front-load the purpose and immediately follow with the prerequisite and output. Every sentence is essential, with no redundant or wasted words.

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?

Given the tool has no input schema and no output schema, the description is fairly complete: it explains what the tool does, what it returns, and its prerequisite. It lacks details on potential errors, URL expiration, or idempotency (annotations note idempotentHint=false, but description doesn't clarify). Still, for a simple initialization tool, it covers the main points.

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 tool has no parameters (0 params, schema coverage 100%). Baseline score is 4 as per instructions. The description adds value by stating the output (authorization URL), which aligns with the lack of input parameters. No additional parameter description is needed.

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 clearly identifies the tool's action ('Start the OAuth 1.0 authorization flow'), the resource ('profile access'), and the output ('Returns an authorization URL'). It effectively distinguishes this from sibling tools like setup_credentials and complete_auth, which are separate steps in the flow.

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 the prerequisite: 'Requires API credentials (setup_credentials first).' This guides the agent on the necessary prior step. However, it does not specify when not to use the tool (e.g., if already authorized) or mention alternatives, but the context is clear for the intended flow.

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