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

Annotations already cover readOnly, idempotent, and non-destructive, so the safety profile is handled. The description adds substantive behavior the annotations cannot convey: entry granularity (one per changed value), ordering (oldest first), the kind taxonomy, and that result completeness varies by subscription plan — a real caveat an agent needs before drawing conclusions from an empty or short result.

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 resource and its record shape, then closes with the optional filters and plan caveat. Mostly efficient, though the first sentence is a long comma-chained list and the plan sentence reads as a fragment.

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 must carry the return-value burden, and it does list the fields and ordering. However, it says nothing about pagination, limits, or volume of entries — meaningful gaps for a log-style endpoint that could return large result sets.

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%, with both since and country already documented in the schema including the YYYY-MM-DD and ISO alpha-2 formats. The description restates the same constraints ('since (YYYY-MM-DD)', 'one country') without adding new syntax or edge-case meaning, which is the expected baseline when the schema does the work.

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 a specific resource (the change log) and states its shape: one entry per changed value, oldest first, with old/new value, kind, effective date, and source. This is far more than a restatement of the name. It stops short of explicitly distinguishing itself from near-siblings like get_finance_law_changes or get_vat_history, so an agent must infer the boundary.

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 plan-tier note ('Developer and Pro: holiday changes; Compliance: every change') tells the agent what data it will get but not when to pick this tool over the sibling history/law-change tools. No explicit when-not or alternative is named, so usage is implied rather than directed.

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