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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, and the description adds real context on top: nothing is deleted, versions and deliveries are retained, only recallability and the paid slot are affected, and a key is required. That clarifies what the destructive flag actually means here rather than merely restating it.

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-loaded with the retire action and its effect, then the non-deletion guarantee and auth requirement, all in tight sentences. The opening pricing preamble ('configure and unfurl free; saving is the paid step') and the raw REST endpoint reference are slightly off-topic filler for an MCP caller.

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 mutation with no output schema, the description covers the effect, the retention guarantee, and the auth requirement, and points to the equivalent REST response shape. It stops short of stating whether retiring is reversible (can the same Watch be re-saved/reactivated), which matters for a destructive-flagged operation.

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?

Only one parameter (watchId) with 100% schema description coverage, so the schema already carries the load. The description adds no format or sourcing detail beyond the schema's 'The saved Watch's id (sw_...)' and the REST-equivalence note, so baseline 3 applies.

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?

Names a specific verb+resource ('Retire a saved Watch') and immediately states the observable effect: it stops being recallable and frees a paid slot. The opening note about configure/unfurl being free and saving being the paid step distinguishes it from save_watch, unfurl_watch, and recall_watch without the agent needing to open any schema.

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?

Usage is implied by the effect statement ('frees its paid slot'), which tells the agent this is the counterpart to save_watch when a Watch is no longer needed. However, it never explicitly says when to retire versus when to use recall_watch or simply leave a Watch alone, and it doesn't state the precondition that the Watch must already be saved.

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