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

No annotations are provided, so the description carries the full burden. It clearly states 'Read-only — safe without user confirmation,' disclosing the safety profile. It also discloses the output structure (id, filename, size, created_on, user_id). This is useful beyond the schema, though it omits pagination or error behavior, which is minor for a simple list operation.

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?

Three sentences, each adding value: purpose, return fields, and usage guidance. No redundancy or filler. The key information is 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?

For a simple tool with one integer parameter and no output schema, the description covers purpose, output fields, safety, and usage context. Nothing essential for an agent to invoke 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 caseId as 'TestRail case id.' The description does not add any extra meaning about the parameter beyond restating the operation context. Baseline of 3 is appropriate since the schema fully handles parameter documentation.

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?

States a specific verb and resource: 'List all attachments on a TestRail case.' It also lists the returned fields, making the tool's function unmistakable. It distinguishes itself from the sibling testrail_get_attachment by explicitly framing this as the precursor to that tool.

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 guidance: 'Use this to find attachment ids before calling testrail_get_attachment.' This directly tells the agent when to invoke this tool and how it fits into a workflow, leaving no ambiguity about its role.

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