zulip

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the tool returns 'all available profile data including custom fields,' which adds some context about output richness. However, it lacks details on permissions, rate limits, error handling, or whether this is a read-only operation (implied but not stated). For a tool with no annotations, this is insufficient.

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 appropriately sized and front-loaded: the first sentence states the core purpose, followed by details on return data and usage. The 'Args' section is redundant with the schema but adds clarity. There's minimal waste, though the phone number example could be more integrated.

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 tool's low complexity (1 parameter) and the presence of an output schema (which handles return values), the description is reasonably complete. It covers the purpose, parameter semantics, and output scope. However, with no annotations, it could better address behavioral aspects like safety or limitations.

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 must compensate. It adds meaning by specifying that the 'email' parameter is 'The user's email address,' which clarifies the expected input format beyond the schema's basic string type. Since there's only one parameter, this is adequate, but it doesn't cover edge cases like invalid emails, so it's not a perfect 5.

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 clearly states the tool's purpose: 'Get information about a Zulip user, including their full profile.' It specifies the verb ('Get') and resource ('Zulip user'), and distinguishes it from siblings like 'resolve_name' or 'get_message_by_id' by focusing on user profiles rather than messages or streams. However, it doesn't explicitly contrast with all siblings, so it's not a perfect 5.

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 provides implied usage guidance: 'Use this tool to look up someone's phone number.' This suggests a specific use case, but it doesn't explicitly state when to use this tool versus alternatives like 'resolve_name' (which might handle user identification differently) or when not to use it. No clear exclusions or comparisons with siblings are provided.

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