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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world operation, so the safety surface is covered. The description contributes beyond that by disclosing what the response contains — prompt text with [brackets] placeholders, pre-send checks, test notes, and a page link — which matters since there is no output schema.

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?

A single sentence with no filler, front-loaded with the verb, resource, and id source before the payload list. The trailing enumeration is long but each item is a distinct returned field, so it earns its space.

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 read tool with no output schema, the description covers the id's origin and the response contents, which is what an agent needs. Pagination and formatting details are unnecessary here, leaving only minor gaps.

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 id property already carries a concrete example, so the schema does most of the work. The description still adds provenance value by telling the agent the id comes from find_messages, which the schema does not say.

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 ("Get one HourSaved message by its id") and enumerates the payload (prompt, checks, testing notes, page link), which distinguishes it from find_messages, whose output is only referenced as the id source.

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?

"(from find_messages)" makes the call order explicit: use find_messages first to obtain the id, then call this. It does not say when to skip this tool or how it relates to find_guides/find_owner_stories, so no exclusions or alternatives are stated.

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