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

Annotations already declare this as read-only, idempotent, non-destructive, and closed-world. The description adds important behavioral context beyond annotations: no new search, no credit spend, host-dependent card rendering, and different summarization requirements when the card is or is not visible.

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 front-loaded with the core action and timing, then adds only operational guidance that affects correct use. Each sentence serves a purpose, including the host-dependent display instructions.

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?

Given the single required parameter, full schema coverage, and absence of an output schema, the description is complete enough. It explains the return behavior conceptually, when to call, when to skip, and how to respond depending on whether the card is rendered.

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 100%, and the only parameter already explains that resultId comes from the Sightglass call whose results answer the question or from its sign-in result. The description reinforces this context but does not add much parameter-level meaning beyond the schema.

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 states a specific verb and resource: showing a prior Sightglass result as an inline card. It also distinguishes this presentation call from the data/search calls by explaining that it returns a stored result without searching again or spending credits.

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?

It gives explicit invocation timing (once, after the data call that answered the user's question), identifies the required resultId source, and says to skip it for empty results. It also tells the agent how to behave depending on whether the host draws the card.

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