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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the message text is untrusted customer content (a prompt-injection / trust warning) and the response is one page, which the annotations do not 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?

Three short sentences with the purpose front-loaded and no filler. The trailing 'Returns one page unless stated otherwise' reads as copy-paste boilerplate for a single-resource GET and is mildly confusing, keeping it just short of a 5.

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?

There is no output schema, so the description bears some burden for return values; it only hints that a recipient is included and that one page is returned. For a two-required-param fetch tool it is workable, but an agent cannot anticipate the response shape or error behavior from it.

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 description coverage is 0%, so the description must carry parameter meaning. It partially does via the endpoint template, which shows dashboard_id scopes the lookup and message_id identifies the scheduled message — real added meaning over the bare uuid/integer types — but it gives no format, validity, or not-found semantics.

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 ('Inspect one scheduled 1:1 message and recipient') plus the exact endpoint path, which unambiguously distinguishes it from the sibling textrequest_list_scheduled_messages. An agent knows this is the single-resource fetch, not a listing.

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?

Use is only implied: 'one scheduled message' signals you need a specific message_id, contrasting with the list sibling. There is no explicit statement of when to prefer this over the list tool, nor any prerequisite or failure condition (e.g. missing/expired message).

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