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

Annotations already cover read-only, idempotent, non-destructive, and closed-world behavior, so the bar is low. The description still adds real value by disclosing ordering (oldest first), that today's live price is appended as the final point, and the interpretation rule that fewer than two captures means the past price is unknown.

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?

A single front-loaded sentence that opens with the core resource and scope before the qualifiers. Every clause carries information, though the trailing parenthetical about capture counts makes it slightly run-on.

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 burden of explaining return values, and it does so: an ordered list of dated captures, an appended current price, and a capture count. It stops short of describing the exact shape of each point, but the agent has enough to call and interpret it.

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% and the schema itself documents the URL format with a concrete example. The description only adds the constraint that it operates on a single product page, which is marginal beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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: dated historical price captures of one product page, sourced from the Internet Archive. The 'Internet Archive' framing implicitly separates it from live-price siblings like product_price and fake_sales, but no sibling is named explicitly.

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 rather than stated: a reader infers this is for checking past prices. There is no explicit when-to-use/when-not, no routing to product_price for current prices or fake_sales for manipulation detection, so the agent must guess the boundary itself.

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