changes_since

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

With no annotations, the description carries the behavioral burden and does real work: it discloses result ordering, the earliest covered date, and the critical negative semantics that a missing tool means 'no change recorded' rather than a stable price. It omits whether the call is read-only and any truncation behavior beyond the schema's limit.

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 tight sentences, front-loaded with purpose and ordering, followed by the one interpretive caveat an agent actually needs. Nothing is redundant.

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-parameter, read-only listing tool with full schema coverage and no output schema, the description covers purpose, ordering, data horizon, and empty-result interpretation. The remaining gap is that it never sketches the shape of a returned change record.

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 adds meaning to 'since' by establishing that records only start in October 2026, implying earlier dates yield empty results. It adds nothing about limit or category, which the schema already documents.

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 description names a specific resource ('software pricing changes Toolradar confirmed on vendor pages'), a scope ('since a date'), and an ordering ('newest first'), which is enough to separate it from get_pricing or search_tools. It never names a sibling explicitly, so the differentiation is implied rather than stated.

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 this is the tool for tracking price changes over time, but there is no explicit when-to-use or when-to-prefer-alternatives guidance. The October 2026 coverage note is a data caveat, not a selection rule.

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