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

Annotations already declare destructiveHint=true and idempotentHint=false, but the description adds genuine behavioral content: the state machine each action drives and the boundary that irreversible cancellation lives in a separate tool. It still omits side effects (e.g., notifications, downstream visibility) and permission requirements, so it is strong but not exhaustive.

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 sentences, no filler, and the operative scope statement is front-loaded before the per-action detail. The cancel_match routing closes the paragraph at exactly the point an agent would otherwise wonder about termination.

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 two-parameter mutation tool with annotations covering the safety profile and no output schema, the description covers purpose, per-action semantics, and the sibling boundary. It could still say what a successful call returns or whether any precondition (e.g., onboarding state) gates approval, but nothing essential to correct invocation is missing.

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 0%, so the description carries the burden and largely does so for `action`: it explains the meaning and effect of each enum value, which the bare enum list does not convey. `matchId` is only noted as universally required, with no hint about where to obtain it (e.g., matches_query), leaving a small gap.

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+resource (modify match state) and immediately enumerates the four supported state transitions, which distinguishes it from matches_query (read) and cancel_match (irreversible termination). An agent can identify the tool's role 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?

Each action is tied to a concrete transition (approve PENDING→ACTIVE, pause ACTIVE→PAUSED, resume PAUSED→ACTIVE, complete ACTIVE→COMPLETED), so the agent knows exactly which action applies in a given state. It also names the alternative explicitly: irreversible cancellation goes to cancel_match, not this tool.

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