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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so 'Does not modify it' largely repeats structured data. The description does add the useful scoping detail that the sender is read from the authenticated workspace, which is not in the annotations.

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?

Two short sentences, no filler, with the core action and its scope front-loaded. Every clause earns its place.

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-only tool with no output schema, the description covers what is fetched and where from. It does not mention what happens when the id is not found or what fields the sender settings contain, but those are minor for this complexity level.

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% for the single 'id' parameter, so the description must carry the meaning; 'by its identifier' confirms this is a sender identifier rather than a name or index. It adds minimal but real clarification over a bare string 'id' field.

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 (Retrieve) and resource (saved sender settings) scoped to the authenticated workspace, and the phrase 'by its identifier' signals single-item lookup rather than enumeration. It does not explicitly name the sibling list_senders, so the contrast with the list operation is only implied.

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?

'by its identifier' implies usage when a known sender id exists, distinguishing it implicitly from list_senders. However, there is no explicit when-to-use statement, no prerequisites, and no named alternative tool.

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