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

Annotations already cover readOnly, idempotent, and non-destructive semantics, but the description adds genuinely new behavioral context: no bearer token is needed for this call, and executing the agent (elsewhere) consumes prepaid run units. That auth and billing context is not derivable from the annotations, though it does not cover rate limits or response shape.

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 tight sentences with the return contents front-loaded and the access/auth caveat second. Every clause carries information; no filler, no restatement of the name.

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-parameter, read-only metadata tool with no output schema, the description enumerates the returned fields and clarifies the auth/billing model, which is everything an agent needs to invoke it correctly.

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 per the rubric the baseline is 4 and there is nothing for the description to disambiguate beyond confirming the call is parameter-free.

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 verb and enumerates the exact resource returned: identity, per-task price, MCP endpoint, and access URL. It also distinguishes itself from the run-execution siblings by explicitly saying it 'does not run the model,' so an agent can separate it from agentfarm_create_run/agentfarm_get_run_result without opening the 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?

It clearly frames the call as metadata-only and notes it requires no bearer token, which tells the agent when this is the right choice versus a billable execution call. It stops short of naming specific sibling alternatives or stating when-not-to-use conditions, so it is clear context rather than full routing guidance.

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