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

Beyond the annotations, it discloses the deprecation timeline (12 months after launch, three emailed notices) and a migration mapping URL, which is genuinely useful behavioral context. The GDPR/PECR sentences add compliance framing but do not describe what actually happens to session state or what the tool returns, so it falls 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?

The deprecation and replacement are correctly front-loaded, but the trailing lawful-basis and PECR subscriber sentences are boilerplate that does not help an agent decide or invoke this tool. Roughly half the text is off-task for a deprecated no-arg call.

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 an output schema present and the deprecation path, migration link, and replacement tool all documented, an agent has what it needs. The legal-basis material is extra rather than missing, so completeness is strong but slightly diluted.

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?

The tool takes zero parameters, so the baseline is 4. The schema description notes the old arguments are unchanged during the deprecation window and are mapped by an adapter, which is adequate for a no-arg tool.

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 states a specific verb and resource ('clears the filters held in the server session') and immediately names the replacement ('Use count_audience instead'). An agent can distinguish this deprecated tool from count_audience without opening either schema.

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?

It gives explicit when-not-to-use guidance ('There is nothing to clear: every count_audience call carries its own audience') and routes the agent to the alternative plus a migration URL. The deprecation window and notice history are also stated.

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