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

With no annotations, the description carries full behavioral burden. It only states that it parses a URL but fails to disclose that the other eight parameters are discarded, that invalid URLs may cause errors, or what the output format is. This is a significant gap for a tool with side effects like parsing.

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, compact sentence with no fluff. It is appropriately short for a simple operation, though it could be slightly more structured by mentioning the relevant parameter. Overall, it is concise and front-loaded.

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?

The tool has nine parameters but only one is used, yet the description does not explain this or the return format. Without an output schema, the agent lacks critical context about what the tool returns (e.g., an object with owner and repo fields). The description is incomplete for a tool with this complexity and no annotation support.

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 schema covers 100% of parameters, but the description adds no meaning beyond it. Critically, the schema lists nine parameters, but only 'url' is relevant to the tool's purpose; the description does not clarify this, leaving the agent to potentially pass irrelevant parameters. The baseline of 3 is lowered because the description fails to guide parameter selection.

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 specific verb ('Parse') and resource ('owner and repo from a GitHub URL'), clearly distinguishing it from sibling tools like figma-url-shape or jira-key-shape. An agent can immediately understand the tool's purpose and scope.

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 guidance is given on when to use this tool versus alternatives. There is no mention of prerequisites, conditions, or when not to use it. The description is purely definitional with no usage context.

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