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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose genuinely useful non-schema behavior: the per-call cost ($0.02) and the exact nature of the returned data. However, it never says whether calls are read-only/side-effect free, whether results are cached or point-in-time, or how 'full' interacts with the other filters — gaps that matter for an unannotated 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 tight sentences with zero filler; the returned content is front-loaded and the cost note is a single trailing clause. Nothing is redundant or padded.

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 annotations and no output schema, the description covers the essentials for a zero-required-parameter query tool: what comes back and what it costs. It is slightly short on behavioral context such as read-only nature and result freshness, but a calling agent has enough to invoke it correctly.

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 every parameter (full, limit, threshold, minCirculating) is already documented in the schema with defaults and bounds — the baseline of 3 applies. The description reinforces the 'largest by supply' and 'depegged' selection logic that limit/minCirculating/threshold implement, but adds no syntax or interaction detail 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 states concretely what the tool returns: every depegged USD stablecoin plus the largest by supply, along with price deviation and 1d/7d supply change. That is a specific resource with defined scope, and it is clearly distinct from the yield- and security-oriented siblings. It stops short of naming those siblings or an explicit 'not for X' clause, so it is clear but not fully differentiated.

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?

There is no statement of when to use this tool versus defi_top_yields, token_security_check, or any alternative, nor any prerequisites or exclusions. The use case (checking peg status) is only inferable from the name and the returned fields. This is the definition's weakest area.

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