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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about the source ('MerchantFlow's retrieval results') and the return fields, which is useful. However, it does not disclose behaviors like whether the id format is validated, what happens for invalid/expired ids, or pagination/truncation of metadata. With annotations covering safety, a 3 is appropriate.

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 with zero waste. The core action and resource are front-loaded, and the return fields are listed compactly. Every sentence earns its place.

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 single-parameter read tool with a rich schema, an output schema, and safety annotations, the description is nearly complete. It could mention what happens when the id is not found or invalid, but the schema's warning about not constructing ids manually partially covers misuse. The output schema likely documents the return shape, so the description need not repeat it.

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 the single parameter thoroughly, including the opaque id format and the warning not to construct it manually. The description adds the return fields but no additional parameter semantics beyond what the schema provides. Baseline 3 is correct.

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 ('Retrieve'), a specific resource ('full record for an opaque document id from MerchantFlow's retrieval results'), and lists the returned fields (id, title, text, URL, metadata). This clearly distinguishes it from sibling tools like search or lookup_order, which have different purposes.

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 description implies usage context: it is for retrieving a full record by an opaque id returned by search. The input schema reinforces this by warning not to construct the id manually. However, it does not explicitly state when to use this tool versus alternatives like lookup_order or get_customer_detail, so it misses the explicit when/when-not guidance that would earn a 5.

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