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

Annotations already establish the safe read-only, idempotent, non-destructive profile, and the description goes further by disclosing plan-tier behavior (Free/anonymous see 7 days, Pro sees full history), the default window, and that the payload includes first-to-last change. This kind of access/quota disclosure is genuine value beyond the annotations, though it omits any mention of response granularity or pagination.

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 core purpose is front-loaded in the opening clause, with qualifiers (chain, N days, plan limits, universe) stacked after. Dense with parentheticals but no wasted sentences; slightly harder to scan than an ideal two-liner.

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 output schema, the description carries the return-shape burden and does say the payload includes the first-to-last change, plus documents plan-scoped history depth. Complete enough to call correctly; only the exact snapshot record shape is left unstated.

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 coverage is 100%, so the baseline is 3; the description nudges above it by clarifying the semantic meaning of the universe values ('rwa' = tokenized assets default, 'stablecoin' = stablecoin pools) and restating the default 30-day window, which the bare enum does not convey.

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 verb+resource: daily snapshots of TVL and TVL-weighted APY for a single symbol, scoped by chain and time window. An agent can distinguish it from summary-style siblings like rwa_market_summary, but it never explicitly contrasts itself with the closest lookalikes (rwa_changes, list_rwa_yields), so it stops just short of full sibling differentiation.

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?

Usage is implied by the description's scope ('one symbol', 'last N days'), but there is no explicit when-to-use or when-to-prefer-an-alternative statement, and no routing to rwa_changes or list_rwa_yields. Adequate but leaves the agent to infer selection.

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