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

Annotations declare readOnlyHint=true, but the description explicitly advertises a state-mutating operation ('record numeric points (with tags)'), which contradicts the read-only claim. The description does add real value elsewhere (wallet-private scope, $0.004 per call up to 1,000 points, $0.016 USDC x402 cost), but the write/read conflict with the annotation is a serious inconsistency.

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-loads the core record/query capability and compression ratio of agg/interval/group_by in a single dense sentence, then appends privacy and pricing. Slightly run-on but every clause carries information an agent needs.

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 9 optional parameters, no required fields, and no output schema, the description covers pricing, isolation, and aggregation options but omits return shape (what a query yields besides the optional PNG), query result limits/pagination, and the semantics of the 'names' action. Adequate but leaves meaningful gaps for a multi-mode tool.

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 only 33%, so the description needs to compensate, and it does partially: it defines the agg vocabulary (avg, sum, min, max, count, last), the interval granularity (minute/hour/day), group-by-a-tag, and chart as an optional PNG. However, key parameters such as from/to, name, and the third action value 'names' are never explained, leaving half the surface undocumented.

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?

Names the specific resource (numeric metric points with tags) and the two concrete verbs (record, query back as time series), then enumerates the exact aggregation and interval options. An agent can distinguish this from siblings like storage, db, memory, or chart without opening the schema.

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 only implied through the action values (record/query/names) embedded in the schema, not stated in the description; there is no explicit 'use this when...' or 'prefer X instead' guidance against the many sibling storage/charting tools. The pricing sentence hints at a cost-sensitive use case but does not tell the agent when to prefer it.

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