get_active_filter

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does state the return values (expression and count, or null), which is useful, but it does not explicitly confirm that the tool is read-only or describe any potential side effects. For a simple getter this is acceptable, but more explicit safety information would be better.

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 description is extremely concise, with two short sentences that immediately state what the tool returns and its purpose. It front-loads the core information and contains no redundant or filler content.

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 zero-parameter getter with an output schema, the description covers the essential context: what it returns, the null case, and why an AI would use it (shared view). The cryptic reference '[5-C]' is unexplained and might confuse, but it is minor. The tool's behavior is well covered given its simplicity.

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 has zero parameters and the schema covers them trivially (100% coverage with none). Per the baseline for zero parameters, a score of 4 is appropriate; the description adds no parameter-specific detail because there are none to explain.

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 clearly states the tool retrieves the currently applied filter, including its expression and matching node count, and returns null if none exists. It also explains the purpose as a shared view for the AI to know what the person is focusing on. It does not explicitly contrast with sibling tools, but the purpose is unambiguous and specific.

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 description implies usage when the AI needs to know the person's current focus (shared view), but it does not explicitly state when to use this over alternatives like get_view_state or suggest_filter. There is no mention of when not to use it or exclusions.

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