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

With no annotations, the description carries full behavioral disclosure. It states that calling this tool writes to the customer's TestRail (a side effect) and returns an attachment_id. It also enforces user confirmation. It doesn't detail failure modes or error handling, but for a simple attachment tool, the key behaviors are transparent.

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?

Two sentences, both functional. The first states the action and key constraint; the second covers mandatory confirmation and the return value. No wasted words, front-loaded with the primary action. Perfectly concise.

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?

For a simple tool with three parameters and no output schema, the description covers the essential context: what it does, the prerequisite (file must exist), the side effect (writes to customer's TestRail), the required confirmation, and the return value. Nothing an agent needs to call it correctly is missing.

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 100%, so the schema already documents all three parameters (caseId, workspacePath, displayFilename) including the requirement that the file exist. The description reiterates the existence requirement and adds context about the workspace path but doesn't introduce new meaning beyond what the schema provides. Baseline 3 is appropriate.

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 ('Attach') with a clear resource ('a file from your /workspace to a TestRail case'), and the scope is explicit. It distinguishes itself from sibling tools like testrail_list_attachments or testrail_get_attachment by focusing on the add action. No ambiguity.

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?

Provides explicit usage instructions: the file must already exist, and it mandates confirmation with the user before calling. This gives clear context on when to use it (after writing a file) and the required permission step. It doesn't explicitly name alternative tools or when not to use it, but the prerequisites and confirmation are strong guidance.

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