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 only the return shape (name and size) and the 'made so far' scope; it says nothing about ordering, pagination, or empty results, and there is no output schema to fill those gaps.

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 short sentence with the resource and return fields front-loaded and no wasted words. It is arguably too terse for the gaps it leaves, but nothing is redundant.

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-only list tool with full schema coverage and clear annotations, the description covers enough to call it correctly and even indicates the return fields. Remaining omissions (ordering, completeness, empty case) are minor for this complexity.

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?

The single document_id parameter has 100% schema description coverage, so the schema carries the parameter meaning. The description adds nothing about which document or how the id is obtained, which is the expected baseline when coverage is complete.

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 (list) and resource (pieces) and even previews the returned fields (name and size). It is distinguishable from ads_read_piece or ads_delete_piece by being an enumeration, though it never names a sibling explicitly.

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?

'Pieces made so far' implies the tool is for enumerating already-created pieces within a document, which is an implicit when-to-use signal. There is no explicit guidance on when to prefer ads_read_piece for detail or how this relates to ads_look_at, so usage remains inferred.

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