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

With no annotations, the description carries the full disclosure burden and largely succeeds: it reveals the nearest-prior-reading lookup semantics, the edge-case behavior for out-of-range dates, the authentication prerequisite, and a read-only posture ('Free to read'). This is substantially richer behavioral disclosure than most definitions provide. There is no contradiction to check since annotations were not provided.

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 first sentence, followed by a genuinely useful edge-case note and the key/watch prerequisite. However, the final four sentences are citation and licensing boilerplate ('cite the page and the read date,' 'may never be compiled into a lead list, a prospecting feed or a sales tool') that do nothing to help an agent select or invoke the tool, roughly doubling the description's length without adding functional value.

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?

Complexity is low — two required parameters, both schema-documented, no annotations, no output schema — and the description covers the input semantics, the returned fields, the out-of-range edge case, and the prerequisite. The only real gap is the absence of an explicit return format, but given the enumerated output fields and the simple shape, the definition is sufficiently complete for correct invocation.

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?

Both parameters are already fully documented in the schema (100% coverage), setting a baseline of 3. The description adds real value beyond the schema by defining the date parameter's semantics: the date is the as-of anchor, and the result comes from the reading held nearest before it. The company parameter gains only the context that the record must be 'one company's list,' so the added meaning is concentrated on the date parameter.

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 first sentence states a specific operation — what one company's list said on a given date, drawn from the nearest reading held before it — and lists the expected return fields (reading date, web-archive capture, source, digest). This point-in-time semantics clearly distinguishes it from siblings like changes or changes_across, though no sibling is named explicitly. The lack of an imperative verb like 'retrieve' keeps it just below the top tier.

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?

The description supplies a prerequisite ('Needs a key on an account whose watch is running') and a scope statement ('part of the watch on disclosedby.com'), which imply when the tool is usable. It also discloses out-of-range behavior ('Says so when the date is earlier than the first reading held'). However, there is no explicit when-to-use guidance or any named alternative such as list or resolve, so an agent must infer which sibling to select.

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