Market Overview

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

Annotations already declare readOnly and non-destructive behavior; the description adds meaningful operational context: the tool is backed by a single call, results are sorted descending by the chosen key, and are capped by limit up to 100. This goes beyond the structured annotations without contradicting them.

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 packs all essential info into three packed sentences plus an example, with no filler. The scope and single-call nature are front-loaded, followed by field list, sorting, and limits — each sentence earns its place.

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 simple read-only tool with two optional parameters and an output schema, the description is complete: it names inputs, outputs (fields and totals), ordering, and the cap, and includes an invocation example. No important behavior is left unexplained.

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 input schema has no descriptions, so the description carries the full burden. It explains that sort accepts open_interest, volume, or premium with a default, and that limit has a default and a maximum of 100, reinforced by a concrete example. This fully compensates for the 0% schema coverage.

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 clearly identifies the tool as a perp market overview with a specific data source ('ONE metaAndAssetCtxs call'), enumerates included fields (mark, open interest, day volume, premium, max leverage, totals), and describes sorting and limits. The 'Perp' qualifier and unique field set distinguish it from siblings like spot_overview and funding_history.

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?

The description gives clear context for when this tool is useful: retrieving a ranked overview of ~233 perps with totals, with sort and limit controls. It does not explicitly name alternative tools or state 'when not to use', but the perp-specific framing and the visible sibling list make the intended usage reasonably clear.

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