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

With no annotations, the description carries the full burden. It usefully discloses the permission ceiling ('cannot mint API keys or write from MCP'), but says nothing about session lifetime, how the session is subsequently used, or what the call returns.

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 compact sentences, with the purpose front-loaded and the restriction immediately after. No filler, though the parenthetical is slightly clipped in phrasing.

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 zero-param session-bootstrap tool with no output schema, the definition covers what the tool is and its limits, but omits the practical mechanics an agent would want: whether a token is returned, its lifetime, and how to use it in later calls.

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 takes zero parameters, so the schema and description have no parameter semantics to reconcile. Baseline 4 applies.

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 ('Create a guest session') and distinguishes itself from account-bearing siblings like veya_account by the 'guest' qualifier. 'On the product API' is slightly vague about which surface, but the core purpose is unambiguous.

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 parenthetical '(Use listing only)' and the note that guests cannot write from MCP give an implicit when-to-use boundary, but no alternative tool (e.g. veya_account) is named for the cases where a guest session is insufficient. Usage is implied rather than routed.

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