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

Annotations already declare destructiveHint=true and idempotentHint=false, but the description goes well beyond them: it warns that owner balance and utilities are lost, explains that a new owner is created on the next paid top-up, describes the confirm gate, and specifies the exact failure response (signature_required). This is rich behavioral disclosure.

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-loads the core action in the first clause, but the sentence is dense with several stacked conditions (confirm, signature, 7-day rule, error code). Every clause carries real information, so it is efficient, though a slightly tighter structure would read better.

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?

With no output schema and destructive annotations covering only the safety profile, the description carries the rest: loss consequences, prerequisites, edge-case eligibility rules, and the error outcome. An agent has everything needed to call this 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%, so the baseline is 3. The description adds meaning beyond the schema by stating when confirm must be true (last passport of an owner with money) and when passport_token is appropriate (client cannot send an Authorization header). That is genuine added semantics over the field descriptions.

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 — 'Detach your passport from its owner' — and clearly distinguishes itself from siblings like join_owner, create_passport, and revoke_passport by defining the detach relationship. An agent can identify the operation 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?

Gives an explicit triggering scenario ('when whoami shows that a stranger paid your top-up') plus concrete conditions and exclusions: confirm: true for the last passport of an owner with money, signature requirement, the 7-day/sole-agent exception, and the signature_required error outcome. When-to-use and when-not are both covered.

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