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

Goes well past the annotations (destructiveHint/idempotentHint) by disclosing the soft-delete retention behavior, the reason requirement, and a specific partial-failure mode — billing refusals returning a `tellHuman` relay sentence that the agent must surface rather than absorb. That is exactly the kind of operational context annotations cannot convey.

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?

Front-loads the operation and its semantics in one clause, then devotes the remainder to the billing failure path. Slightly long and the all-caps emphasis is heavy-handed, but every sentence carries actionable information.

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?

No output schema exists, yet the description covers the one response condition an agent must handle (billing refusal with `tellHuman`) and explains why continuing read-only work is not a valid fallback. Complete for a two-parameter mutation with strong annotation coverage.

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 50%; `attachment` is self-documented and `reason` is bare. The description adds only that the reason is required (already in the schema's required list) and says nothing about expected reason content, length, or format. Baseline 3 fits a two-parameter tool where the schema does most of the work.

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+resource and immediately disambiguates semantics with 'the delete-equivalent — keeps it as a record,' which separates it from a hard delete and from the read-oriented siblings like get_attachment and list_attachments. An agent knows exactly what state change this performs.

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?

Makes the use case explicit (retire an attachment without destroying the record) and states that a reason is mandatory, plus detailed guidance on what to do when the call is refused for billing. It stops short of naming a sibling alternative or stating when this is preferable to leaving the attachment active.

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