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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds value by enumerating the returned fields (status/dates, name, IP, custom properties, segments), which matters because there is no output schema. It gives no detail on what happens for an unknown id or any rate/permission constraints.

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 telegraphic sentence plus the REST endpoint; zero padding and the return-field list is front-loaded. The fragment style ('One subscriber by...') is slightly clipped but nothing is wasted.

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 annotations covering safety and no output schema, the description carries the essential pieces: identity semantics and the shape of the response. Missing only edge-case behavior (not-found handling) and any differentiation from the similarly named sibling.

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, and the schema fully documents it (100% coverage, 'NewsMAN subscriber id', string or integer). The description restates 'by subscriber_id' without adding format, source, or lookup-failure semantics, so the 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?

States a specific verb and resource ('one subscriber by subscriber_id') and enumerates what comes back (status, dates, name, IP, custom properties, segments), so the agent knows this is a single-record retrieval. It does not distinguish itself from the sibling newsman_get_subscriber or from newsman_search_subscribers, which is the main clarity gap.

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?

There is no guidance about when to use this versus newsman_get_subscriber, newsman_search_subscribers, or newsman_list_subscribers. The presence of both newsman_get_subscriber and newsman_get_subscriber_by_id in the sibling list makes this omission costly — the agent must guess which lookup key each expects.

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