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

Annotations already declare readOnly, idempotent, closed-world and non-destructive behavior, so the core safety profile is covered. The description adds genuinely non-obvious context the annotations cannot: receipts are retained only within a warm instance, so a fetch may fail or be lossy after the fact. It stops short of saying what happens when the receipt is unavailable.

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 load-bearing: the first defines the return payload, the second delivers the retention caveat and its operational consequence. The key warning is front-loaded in the second sentence with no filler or restated title.

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 single-parameter read tool with no output schema, the description covers what is returned, where the ID comes from, and the ephemerality constraint that governs whether calling it is worthwhile. Only the not-found/failed-fetch behavior is left unaddressed, which is a minor gap.

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 100% and the single parameter already documents its expected 'tr_exec_...' format sourced from invoke_capability. The description adds no further meaning about the identifier or its scoping, so the schema is doing all the work — the baseline 3 applies.

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?

Uses a specific verb and resource ("Fetch the TRACE Receipt for an execution_id") and enumerates the returned contents (status, commitments, artifacts, evidence). It does not explicitly name a sibling to contrast with, but the receipt-retrieval purpose is unambiguous against find_routes, get_quote, or invoke_capability.

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?

The second sentence implies this tool is for durable verification rather than the normal path, since the invoke response already carries the full receipt inline. That is useful steering, but it is stated as a caveat rather than an explicit "use this when / use invoke_capability instead when" rule, and no failure or missing-receipt case is described.

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