zulip

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly explains the tool's read-only nature (implied by 'Get'), the specific output format ('Returns a markdown link like [#stream > topic](url)'), and the URL encoding requirements. However, it doesn't mention potential errors (e.g., invalid message_id) or rate limits.

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 efficiently structured with a clear purpose statement, critical usage guidelines, output format explanation, and parameter documentation—all in four focused sentences. Every sentence adds value without redundancy.

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 (single parameter), no annotations, but an output schema (which handles return values), the description is complete. It covers purpose, usage rules, behavioral context, and parameter semantics adequately for this straightforward lookup tool.

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 input schema has 0% description coverage, so the description must compensate. It documents the single parameter (message_id) and explains its purpose ('The message ID'), adding essential meaning beyond the schema's type information. However, it doesn't specify where to find message IDs or validation rules.

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 specific verb ('Get a permalink') and resource ('for a Zulip message'), distinguishing it from siblings like get_message_by_id (which retrieves message content) or send_message (which creates messages). The purpose is unambiguous and differentiated.

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 explicit guidance on when to use this tool ('Always use this tool to generate Zulip message links') and when not to ('Never construct Zulip URLs manually'), with clear reasoning about URL format complexities. It effectively distinguishes this from manual URL construction alternatives.

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