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

Annotations provide idempotentHint=true, destructiveHint=false, and readOnlyHint=false. The description adds crucial behavioral detail about the double opt-in mechanism ('NOTHING counts until they click the confirmation email themselves'), which is not inferable from annotations. This is valuable beyond what structured fields convey, though the description doesn't specify response format or potential side effects other than the pending state.

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 compact and front-loaded with the core purpose, then immediately details the critical behavioral constraint (double opt-in) and the usage condition. Every sentence adds unique value, with no redundancy.

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 tool with only two optional parameters and no output schema, the description covers the essential aspects: what it does, when to use it, the key behavioral side effect (double opt-in), and the constraint on agent action. Nothing critical is missing for an agent to decide 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?

Schema description coverage is 100%. The schema already includes descriptive text for both parameters, including the explicit warning that email must be 'the person who ASKED to join — never a guessed one'. The description adds no additional usage nuances for parameters beyond what the schema provides, so a baseline 3 is appropriate.

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 ('Put someone in line'), a specific resource (Measure Tech PRO web console waitlist), and a context (at founding pricing). It clearly distinguishes the action from siblings like request_contact or heart_request by focusing on the waitlist enrollment action.

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 'Use only when the person explicitly asked to join', providing a clear condition for invocation. It also notes 'an agent can only ever start the ask', which implies the agent cannot complete the process unilaterally. It doesn't name sibling alternatives explicitly, but the condition is clear enough to prevent misuse.

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