get_contacts

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It discloses the purpose and scope (external contacts, registered in account), but does not mention potential side effects (none expected for a list) or any behavior like pagination, ordering, or data freshness. For a read-only list operation, this is adequate but could be richer.

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 a single sentence with no fluff. It's front-loaded with the verb and resource, and is appropriately concise for a tool with no arguments.

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?

Given the complexity is low (no params, no output schema, simple list operation), the description is mostly complete. It defines the resource clearly enough for an agent to know what it returns. However, it doesn't specify the return format or fields, which could be helpful but is not critical for calling it 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?

The tool has zero parameters, and schema description coverage is 100%, so the schema provides all needed info. The description doesn't need to add parameter semantics, and with no params, the baseline is 4 per instructions. The description adds nothing about parameters, but it's not necessary.

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 clear verb ('List') and resource ('external contacts (clients)'), and notes the scope is 'registered in the account.' It distinguishes from sibling tools like get_members, which likely list team members, but it doesn't explicitly mention that distinction. It's clear but not fully differentiated from get_members.

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 implies usage when you need external contacts or clients, but it does not explicitly state when to use this vs. alternatives like get_members. It mentions 'registered in the account' which provides some context, but no exclusions or comparisons to siblings are given.

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