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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is largely covered. The description still adds genuinely useful behavior: the required member permission ('See your profile', profile:read) and the sign-in prompt behavior when the member has not connected the app. The prompt-injection warning is boilerplate but relevant to a tool returning member-authored content.

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?

The core statement is front-loaded, but the second sentence ('The keys of the profile sections your member chose not to show...') is a fragment restating the first, and the closing injection warning is generic boilerplate repeated across this tool family. Permissions and auth behavior sit in the middle where they are easy to skim past.

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 zero-parameter read tool with no output schema, the definition covers purpose, return semantics, permission requirement and auth fallback—everything needed to call it correctly. The only real gap is the missing cross-reference to the write counterpart for changing visibility.

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?

The tool takes zero parameters, so the baseline is 4 and the schema has nothing to document. The description does useful adjacent work by explaining what the returned keys mean and that their absence implies visibility, though there is no output schema to confirm the exact response shape.

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 ('Read which of your member's profile sections are hidden') and even defines the semantics of the result: keys are the sections the member chose not to show, every other section shows. It does not name the counterpart write tool set_my_section_visibility, so the get/set distinction is left to inference from the naming convention shared by siblings like get_my_feed_visibility.

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?

Usage is implied rather than stated: an agent can infer this is the read side of section-visibility management, and the 'hiding only ever removes a section from view' line clarifies the domain model. However, there is no explicit when-to-use framing and no pointer to set_my_section_visibility for changing the setting, which is the obvious alternative an agent would need.

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