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

Annotations already cover the safety profile (readOnlyHint, destructiveHint false, openWorldHint), so the description adds the behaviors the annotations cannot: that the result opens as an interactive dashboard, that row clicks request charts/analysis, and that non-app clients can read the `summary` field. These are material invocation-shaping details beyond structured fields.

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?

Front-loaded with purpose and triggers before coverage, exclusions, and interaction behavior. Each sentence carries distinct routing or behavioral information; the example utterances earn their space by supporting semantic selection.

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?

With no parameters and an output schema present, the description need not document returns, yet it still tells the agent how output is surfaced (interactive board, `summary` fallback) and what the board contains. Nothing needed to call the tool correctly 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?

The tool takes zero parameters, so the baseline of 4 applies. The description correctly adds no parameter guidance, and none is needed since the schema is empty and closed (additionalProperties false).

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?

Names a specific resource ("the user's live market board") with a clear role statement ("Start here when they ask how the markets are doing in general") and enumerates its contents: watchlist, most-asked symbols, indices, VIX, crypto, commodities, FX. It distinguishes itself from sibling tools by name (market_snapshot, my_watchlist, per-symbol tools), so an agent can route without opening a schema.

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?

Gives explicit trigger utterances, an explicit exclusion ("Don't also call market_snapshot for the same overview"), a rule for extending with other tools ("add other tools only for what the board doesn't show (futures, news, sectors)"), and a redirect for the single-symbol case. This is as complete a when/when-not/alternatives statement as the dimension allows.

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