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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, but the description adds meaningful context beyond them: published figures are not current quotes, captured source numbers and selection are reused, and expired evidence requires an explicit new read. It does not need to explain return values because an output schema exists.

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 is reasonably tight. A few clauses are dense, and the fragment 'A published edition and its chapters' is slightly awkward, but every sentence contributes useful guidance.

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 read-only display widget with full schema coverage and an output schema, the description covers the key dependency, visual-use condition, data staleness caveat, and exclusions from broader interpretation or data-fetching roles. Nothing essential for correct invocation is missing.

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%, so both evidence_id and chapter_id are already documented in the schema. The description adds context about evidence reuse and expiry, but it does not directly elaborate on chapter selection or parameter syntax beyond what the schema provides.

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 a specific verb ('Display') and resource ('published market update widget') and clarifies that it shows a published edition and chapters. It also distinguishes the tool from data-fetching, calculation, navigation, and interpretation tools, so an agent can identify its role without checking siblings.

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 states the prerequisite ('after evidence from research_briefing is available') and a clear condition for use ('Use only when a visual helps answer the question'). It also lists explicit exclusions: 'Not a data fetch, calculation, navigation hub or replacement for the assistant's interpretation.'

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