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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds useful behavioral context beyond annotations by disclosing the return shape (kept/removed indices or deduped texts) and placement in a pipeline. It does not mention threshold-driven behavior or edge cases, which keeps it from 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 description is structured into Purpose, When to use, When NOT to use, Returns, and Composes with. It is front-loaded and every section adds useful, non-redundant information.

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?

Given a simple two-parameter read-only tool with full schema coverage and an output schema, the description is complete. It covers purpose, usage boundaries, return shape, and composition, leaving no material gap for an agent to call it correctly.

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 description coverage is 100%, so both parameters are already documented in the schema. The description reinforces that this is semantic rather than exact deduplication, but it adds no additional syntax or threshold guidance beyond what the schema provides. Baseline 3 applies when the schema carries parameter semantics.

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: semantic deduplication across multiple text passages via SemHash. It clearly distinguishes the tool from siblings by naming composition with smart_search and smart_context_gate, so an agent can identify the right tool without opening the 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 explicitly gives both when to use and when NOT to use: overlapping chunks or search results versus a single string or unrelated documents. It also names adjacent tools, making the selection boundary concrete.

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