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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, and the description adds genuinely new traits: a 12-month sunset after three emailed notices, returned fields (codes with counts, did_you_mean for near misses), and an audience-scope caveat that sole traders and ordinary partnerships are excluded unless a toggle changes. The GDPR/PECR lawful-basis sentence is somewhat boilerplate and dilutes focus, keeping this short of a 5.

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?

Deprecation and the replacement tool are correctly front-loaded, but the closing sentence on legitimate interests and PECR subscriber defaults reads as boilerplate that an agent must parse around. The return-value and migration content earns its place; the legal paragraph only marginally does.

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?

An output schema exists, so return values need not be spelled out; the description nonetheless covers deprecation timing, the migration path, and the data-scope caveat. What remains missing is anything about this tool's behavior differing from search_filter_values during the transition window itself.

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?

Zero parameters, so the baseline is 4. The description usefully notes that the old arguments are unchanged during the deprecation window and are remapped by the adapter, which explains why the schema is empty.

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?

Opens with a specific verb and resource ('searches the values of one filter category') and immediately names the replacement, search_filter_values. An agent can distinguish it from the sibling without opening any schema, and the 'Deprecated' prefix frames the whole purpose.

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?

Explicitly directs the agent to use search_filter_values instead, which is a clear when-not-to-use rule plus the named alternative. The migration URL provides a concrete next step for every call shape.

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