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

Annotations only declare readOnlyHint=false and openWorldHint=false; the description adds that the call 'needs a token,' which is genuine auth context beyond the annotations. It still omits the consequence of leaving (e.g., whether a spot or credits are forfeited), so the behavioral picture is incomplete but not empty.

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 short clauses with no wasted words, and the primary action is front-loaded ahead of the parenthetical auth note. The parenthetical is slightly awkward but does not bloat the text.

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 action tool with no output schema, the description covers purpose, precondition, and auth needs. It falls short on the outcome of leaving — an agent calling a mutation on a swap circle would benefit from knowing what is lost or returned.

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 baseline of 4 applies. There is nothing for the description to clarify beyond the empty 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?

States a specific verb (leave) and resource (swap circle) plus a scoping condition (while it is still filling), which implicitly contrasts with join_swap_circle. An agent can distinguish it from sibling circle tools without opening a 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?

The phrase 'while it is still filling' implies a timing condition under which the tool applies, giving implied usage guidance. However, it never names the alternative (join_swap_circle) or states when-not to use it, so the guidance remains inferred rather than explicit.

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