chat_unfurl

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 only states the basic function without revealing permissions required (e.g., scope needs), side effects (e.g., modifying message appearance), or constraints (e.g., only for bot messages). A user or agent has no insight into the tool's implications.

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 of 7 words, which is extremely concise. While there is no waste, the brevity comes at the cost of necessary detail. It is adequately structured for a brief statement but lacks critical information that should be present.

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 has 7 parameters and an output schema, the description is incomplete. It does not explain the relationship between parameters (e.g., channel and ts identify the message, unfurls defines the preview), nor does it describe the output. The agent cannot reliably determine how to use the tool without external knowledge.

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 coverage is 0%, meaning the input schema provides no descriptions. The tool description does not clarify any of the 7 parameters (e.g., channel, ts, unfurls, user_auth_*). The agent is left to infer meaning from parameter names alone, which is insufficient for correct invocation.

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 'Provide custom unfurl behavior for URLs in messages' clearly identifies the tool's purpose with a specific verb and resource. It distinguishes from generic chat tools by referencing 'unfurl behavior,' which is a Slack-specific concept. However, it could be more explicit about customizing URL previews.

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 usage context or alternatives are mentioned. The description does not differentiate from sibling tools like chat_post_message or chat_update, nor does it specify scenarios where unfurling is applicable. Given the lack of annotations, the agent receives no guidance on when to invoke this tool.

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