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

Annotations already declare destructiveHint=true and idempotentHint=true; the description adds real value on top by spelling out the observable consequence (files can no longer be printed or downloaded) and making idempotency concrete ("A session that has already ended returns status expired"). It also flags that the manage_token is secret. It does not say whether session data is deleted or only access is revoked, which is the main remaining behavioral gap.

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 short sentences, each carrying load: effect, token provenance, and expired-session behavior. The most important fact (what ending does) is front-loaded.

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 one-parameter destructive call with an output schema and full annotation coverage, the description supplies what's needed to invoke it correctly: the token's origin, its secrecy, and the already-expired response case. Missing only a note on whether data is retained after expiry and whether any confirmation should precede the call.

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 100% and the single parameter is already documented as the secret from create_print_session with the note that a label and PIN do not work. The description restates the same facts (token source, secrecy) without adding format or validation detail, so this is baseline rather than added meaning.

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 and resource ("End a Preesy session") plus the concrete effect (files can no longer be printed or downloaded), which an agent can act on immediately. It stops short of naming the sibling it is distinguished from (set_print_only, which restricts printing without ending the session), so the boundary is only implicit.

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?

Gives clear context: use it when you want to terminate access to the session's files, and it explicitly says where the required token comes from (the create_print_session result earlier in the conversation). No explicit "do not use when..." exclusion versus set_print_only, but the usage condition is unambiguous.

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