Every market

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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the safety profile is covered. The description adds genuinely non-structured context: no API key is required, and it discloses the shape of each returned record (category, related markets, per-plan series counts, lanes).

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 the resource and scope, then the return fields, then the follow-up call. It is a single dense sentence whose embedded clause ('how many series each plan holds of it') reads awkwardly, but no sentence is 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?

There is no output schema, so describing the per-entry fields is necessary and done here. Combined with the no-auth note and the handoff to tilla_market, an agent has enough to call it and use the result; only response size/pagination behavior is unstated, and 'every market' implies none.

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?

Zero parameters, so the baseline is 4. The description adds cross-tool semantics by naming `id` as the key to pass to tilla_market, which is useful even though it isn't a parameter of this tool.

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?

States a specific resource (every market TILLA carries) and enumerates the covered asset classes (crypto, US stocks/ETFs, FX, macro), plus what each entry includes. It is clearly distinguishable from the sibling tilla_market, which handles a single market, because the description tells the agent to take the `id` there.

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?

Explicitly routes to tilla_market via the returned `id`, giving a clear usage path. It doesn't state exclusions against other enumeration-ish siblings (tilla_inventory, tilla_tiers, tilla_sample), so the when-not is implied rather than stated.

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