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

Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds meaningful context beyond those annotations by stating the result is 'non-secret' and that the tool 'does not inspect a user device or wallet,' which clarifies privacy and safety expectations for an agent.

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 description is two tightly written sentences with no filler. The primary return value and scope are front-loaded, and the safety clarification is placed at the end without adding unnecessary length.

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 single-parameter read-only tool with no output schema, the description covers what is returned and what the tool does not do. It is slightly incomplete only in that it does not tell the agent how to obtain or format a valid screen_id, which is the sole input.

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 compensate for the undocumented screen_id parameter. It does not describe how screen_id should be sourced, what it represents beyond 'screen,' or how it relates to sibling tools such as list_app_entry_points. The regex pattern in the schema provides format but not semantic meaning.

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?

The description uses the specific verb 'Return' and identifies the resource as 'a non-secret semantic description of an important Aperture screen.' It also enumerates the content of the result (purpose, entry points, sensitivity, safe agent actions), which makes the tool's function unambiguous and distinct from sibling get_* and list_* tools.

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?

The intended use is implied by the description: call this when you need a semantic screen description rather than raw data. However, it does not explicitly state when to prefer this over siblings like list_app_entry_points or get_feature, and it names no alternatives or exclusion conditions.

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