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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context about the return scope: it returns the document in full, including the attachment gallery, which is not implied by the schema alone.

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 short sentences with no redundancy. The primary action and scope are front-loaded, and the identifier requirement is stated compactly in the second sentence. Every word 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 fetch tool, the description is largely complete: it explains what is fetched and how to identify the document. The lack of an output schema and the fact that no parameters are marked required make the explicit 'either/or' instruction valuable. Minor gaps, such as behavior when both id and external identifiers are supplied, keep it from a 5.

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%, so the baseline is 3. The description adds important relational semantics by specifying the alternative identifier patterns: either `id` alone, or both `releaseProgram` and `externalId`. This goes beyond the individual property descriptions and clarifies a constraint not represented in the schema's required fields.

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 uses a specific verb ('Fetch') and a specific resource ('one archive document in full'), and adds the distinguishing detail that it includes the attachment gallery. This clearly separates it from sibling tools like search_documents or related_documents.

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?

It provides clear operational context: use this tool when you need a single full document, and it states the valid identifier combinations. It does not explicitly name alternatives or exclusions, but the 'one archive document in full' framing makes the intended scope clear.

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