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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and non-destructive behavior, so the safety profile is covered. The description adds that a call can span all markets or one, but says nothing about price freshness, update cadence, or how oracle differs from mark price — meaningful behavior for a pricing tool.

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?

Two short sentences, front-loaded with the resource and scope, with no filler. The quoted example question is slightly informal but does convey intent efficiently.

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 rich annotations, full schema coverage, zero required parameters and an output schema, the description covers what an agent needs to invoke it correctly. The only real omission is explaining the oracle-versus-mark distinction and the precedence between symbol and pair_id.

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 the two optional parameters (symbol and pair_id) are already documented with examples in the schema. The description only reinforces that either a single market or all markets can be requested, adding no syntax or precedence guidance 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 names the specific resource (oracle and mark prices) and its scope (every market or a single one), so an agent can tell it apart from siblings like get_candles or get_orderbook. It is clear but does not explicitly contrast itself with those 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?

"for every market or one" implies the filtering choice, and the embedded example question ("What is the ETH price?") gives a concrete usage cue. There is no explicit statement of when to prefer this over get_markets or get_candles, nor any exclusions.

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