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

Adds substantial context beyond the annotations: auth is required, exactly one confirmation email is sent and nothing else until confirmation, the returned status lifecycle is spelled out, and idempotency is stated in plain language ('Calling again for the same email is safe'), aligning with idempotentHint=true and openWorldHint=true. It does not address why destructiveHint=true is set (what state is created/affected), leaving one annotation unexplained.

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?

Front-loaded with the usage condition, then side effects, then inputs, then return shape — a sensible information order with no filler sentences. It is dense, but every clause (auth, single email, no further mail, idempotency) carries a decision-relevant fact.

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?

Despite there being no output schema, the description documents the return object and its status values, covers required auth, describes the email side effect and the pending-until-confirmed lifecycle, and confirms safe repeat calls. An agent has everything needed to call this correctly and to set expectations for the user.

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 coverage is 100%, so the baseline is 3, but the description adds usable semantics: it labels which inputs are required vs optional and restates the digest default ('immediate (default)'), which helps an agent decide whether to supply digest at all. It does not add format or validation detail beyond the 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 and resource ('Register a human owner') plus the observable effect (the human receives progress updates by email and can reply). It is clearly distinguishable from siblings like cooper_confirm_owner (which completes the flow) and cooper_notify_owner (which pushes an update).

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?

Opens with an explicit when-to-use condition ('Use this when a human should receive the agent's progress updates by email and be able to reply with instructions'), which tells the agent the scenario that selects this tool. It does not name an alternative or an exclusion (e.g., 'use cooper_confirm_owner once they click the link'), so it falls short of full routing guidance.

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