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

Annotations already signal read-only and non-destructive behavior; the description adds meaningful context beyond that: short-lived signed link, inline preview rendering, lifetime coupling to privacy mode, and the content-scope requirement. No contradiction with readOnlyHint is present because creating a signed link does not imply mutating persistent state.

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?

Packs the key decision trigger, behavior, and a security requirement into four short sentences. The most actionable guidance ('ALWAYS call this when...') is front-loaded, with no redundant filler.

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 tool with one required parameter, full schema documentation, read-only annotations, and an output schema, the description supplies everything the agent needs to select and invoke it correctly: what it returns, when to use it, lifetime behavior, and required scope.

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 coverage is 100%, so the schema already documents every parameter thoroughly. The description adds contextual value like privacy-mode-based linking and content scope, but does not need to restate per-parameter 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?

Uses a specific verb and resource: 'Creates a short-lived signed link' showing current display content. The 'RIGHT NOW' and 'rendered inline as a preview widget' wording clearly differentiates it from broader display or read operations.

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?

Provides explicit trigger guidance: 'ALWAYS call this when the user wants to SEE their display or screen content (preview, zeig mir das Display).' It does not name specific alternative tools or state when not to use it, but the usage context is unambiguous.

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