list_contacts

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

No annotations are provided, so the description carries full burden. It does convey a meaningful behavioral constraint: only owner-approved relationships and only those visible to the credential, implying scoping/filtering. But it omits return format, pagination, and why the credential-scoped visibility matters.

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?

Single, front-loaded sentence with no filler. Efficient, though the jargon density slightly hurts readability.

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?

An output schema exists, so return values need not be explained. For a zero-param list tool, the description conveys the key scoping behavior. Minor gap: no usage routing against siblings.

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?

Zero parameters, so baseline is 4. Nothing to misdocument.

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 (List) and resource (CoS relationships / contacts), which is clearer than a tautology. However, 'owner-approved CoS relationships visible to this credential' is jargon-heavy and doesn't clearly distinguish what this resource actually is against siblings like get_identity or read_inbox. An agent knows it's a list operation but not exactly what it retrieves.

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?

No when-to-use guidance, no exclusions, and no reference to alternative tools. The description doesn't help an agent decide between list_contacts and get_identity when looking up a person.

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