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

Annotations already declare readOnlyHint=true, so the safety profile is covered, but the description adds nothing further — no statement about behavior when the id is unknown, whether the receipt is immutable, or what a receipt represents. With annotations the bar is lower, yet there is still no added context.

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 definition is a single short fragment with no wasted words, but it is not a complete sentence and front-loads a noun phrase rather than an action. Brevity here comes at the cost of specification rather than from tight editing.

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 one-parameter read with no output schema, an agent still needs to know what a 'decision receipt' contains and what happens on a miss. Neither is covered, and no output schema exists to fill the 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 description coverage is 0%, so the description must carry parameter meaning; it partially does by revealing the expected id prefix ('rcpt_…'), which the bare string type does not. It still says nothing about id validation, length, or scope of lookup.

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 fragment names the resource ('decision receipt') and the lookup key ('by id (rcpt_…)'), which implies retrieval, but supplies no verb and largely restates the title 'Fetch a receipt'. It does not distinguish the tool from the sibling verify_receipt beyond the implied read-vs-verify difference.

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?

There is no when-to-use guidance, no mention of when to prefer verify_receipt, and no prerequisites or error conditions. The only hint is that an id is required, which the schema already states.

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