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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real value beyond them by disclosing the payload composition – subtasks, messages and attachments are included, which is beyond what the annotations state.

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?

One sentence, front-loaded with the verb and resource, with the payload enumeration trailing. There is no filler or duplication.

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?

There is no output schema, so the description's enumeration of returned content (subtasks, messages, attachments) does useful work in setting expectations. It stops short of describing depth limits (e.g., how many messages or whether attachments are metadata only), but is sufficient for a simple two-param read tool.

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 both parameters are already documented in-schema, giving a baseline of 3. The description's emphasis on 'relative ID' mildly reinforces the piece_relative_id semantics but adds nothing about the account_code format that the schema lacks.

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 ('Read comprehensive details') and resource ('a single piece') plus a clear lookup key ('by its relative ID'). The word 'single' cleanly separates it from sibling list-style tools like ListPiecesTool and SearchPiecesTool.

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 phrase 'of a single piece ... by its relative ID' implies when to call it (when you have an ID and want full detail rather than a list), but no alternative or exclusion is named. An agent must infer the ListPieces/SearchPieces boundary itself.

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