get_test_result_attachment

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description contributes the one thing annotations cannot: that the returned content is base64-encoded, which is critical since there is no output schema and an agent would otherwise not know how to interpret the payload. It stops short of noting size limits or behavior when the attachment is missing.

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?

A single compact sentence that front-loads the action and resource, then immediately supplies the return-value encoding. No filler, no redundant restatement of the tool name.

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 two-parameter read tool with no output schema, the definition covers what the agent most needs: what it fetches and how the content comes back (base64). Remaining gaps are minor — the meaning of attachmentId and failure behavior — against annotations that already establish it is a safe read.

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 only 50% — the 'id' parameter is documented as a test result UUID, but 'attachmentId' has no schema description at all. The description adds nothing about either parameter (formats, where IDs come from, whether attachmentId is scoped to the test result), so it fails to compensate for the coverage gap.

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 gives a specific verb+resource pair, 'Download a test result attachment', which is clearly distinct from list_test_result_attachments, upload_test_result_attachment, and delete_test_result_attachment. It does not explicitly contrast with the generic get_attachment, but the resource qualifier 'test result' does most of the disambiguation work.

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?

Usage is only implied: the word 'Download' suggests fetching binary content rather than metadata, which nudges an agent away from get_attachment_metadata. There is no explicit statement about when to prefer this over get_attachment or list_test_result_attachments first, and no prerequisites or error conditions are mentioned.

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