setup_credentials

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

With no annotations, the description carries the full burden. It states that credentials are set up for the session, but does not disclose side effects, whether it overwrites existing credentials, requires authentication (beyond the IAM token itself), validates input, or returns a confirmation. The presence of an output schema is not leveraged in the description.

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 a single sentence with no redundant information. It is appropriately front-loaded and easy to parse.

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 that this is a state-changing setup tool with no annotations and no explanation of session behavior, the description is incomplete. It should mention that it initializes the session for subsequent Yandex Cloud operations, possibly that it replaces existing credentials, and any invocation prerequisites.

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 descriptions for both iam_token and folder_id fully cover the parameter semantics (format and type). The tool description adds no further explanation about how these parameters are used, so it provides no value 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 uses the verb 'Setup' with the resource 'Yandex Cloud credentials' and specifies 'for the session', which distinguishes it from persistent credential management. However, 'setup' is somewhat generic and could be more explicit (e.g., 'configure' or 'store'), so it's clear but not perfectly differentiated.

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 provides no guidance on when to use this tool relative to siblings like get_credentials_status or clear_credentials. It does not mention prerequisites, ordering, or alternatives.

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