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

Beyond the annotations (destructive/idempotent/not-readOnly), it discloses the optimistic-concurrency rule (expectedVersion 0 creates, a matching current version updates), the 30-day retention window, and an explicit negative scope. It doesn't say what happens on a stale version (reject vs overwrite) despite destructiveHint=true, leaving the risk profile partly inferred.

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?

Three dense, front-loaded sentences that each carry distinct information and end with a crisp negative scope. It is information-rich rather than padded, though the packing of versioning rules into one sentence is slightly terse.

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 mutation with an output schema, it covers retention, concurrency, and non-goals, which is most of what an agent needs. The remaining gap is the unexplained required 'confirmedSave' flag and stale-version behavior, but overall it is sufficient to call the tool correctly.

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?

With 0% schema description coverage the description must carry parameter meaning, and it only partly does: it explains expectedVersion semantics and maps documentId ('optional owned PDF reference'), service, sender, recipient and options. 'key', 'label' and especially the const-true 'confirmedSave' remain unexplained, leaving a required guard flag opaque.

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 names a specific verb+resource (stores/saves a correspondence draft) and scopes it to 'private preparation details for one intended physical delivery.' It is clearly distinguishable from delete_draft or drafts, 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?

It gives a trigger ('after the user asks to save a draft') and useful exclusions ('Does not generate a quote, approve, pay, or send'), effectively routing the agent away from postedly_quote and postedly_checkout. It does not name a concrete alternative tool for editing an existing draft, so no full 5.

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