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

With no annotations, the description does real work: it discloses sort order (newest first), that results are limited to price records only, and what the initial_record marker means. It leaves the read-only nature implicit and does not say whether the limit truncates silently or how defaults are applied, but the important behavioral traits are covered.

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 sentences, front-loaded with what is returned and its ordering, followed by the one semantic caveat an agent needs. 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?

For a three-optional-parameter list tool with no output schema, the description covers scope, ordering, and the meaning of one return field. It does not sketch the remaining row shape (plan, old/new price, currency), so an agent knows how to call it but only partially what it will get back.

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 slug, limit, and since are already documented with their defaults in the schema. The description reinforces slug ("optionally for one tool") and since ("since a date") but adds no format or interpretation detail beyond that, so the baseline of 3 applies.

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 and resource: recorded price changes, with ordering (newest first) and an optional per-tool scope. It reads clearly as a historical price-change listing, though it never explicitly contrasts itself with siblings such as compare_tools or get_tool.

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: an agent can infer it should call this to see what prices moved over a period, and the clause "Price records only" acts as a scoping caveat. There is no explicit when-to-use versus alternatives, nor any when-not guidance.

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