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

Annotations cover the safety profile (readOnlyHint, openWorldHint), and the description adds behaviors they cannot express: the hard 500-item limit, that normalization covers case/accents/punctuation, that semantic matching uses multilingual embeddings with a cosine threshold, and the $0.004 USDC per-call x402 cost. Cost and cap disclosure is genuinely useful; it stops short of saying how over-limit input or embedding failures are handled.

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?

Three tight sentences: the operation and its two matching modes first, the return contract second, the price last. Every sentence carries information, though the middle clause packs embeddings, cosine threshold and multilingual scope into one dense phrase.

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?

There is no output schema, so the description usefully states the return shape (unique list plus duplicate groups), and it discloses the cost and item cap an agent needs before calling. Gaps remain around over-limit behavior and the semantic/threshold interaction, but nothing essential is omitted for a three-parameter tool.

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 only 33% (only threshold is documented in the schema), so the description must compensate. It does clarify that items is the string list to deduplicate and that semantic toggles meaning-level matching, but it never states the boolean's default explicitly nor reconciles the threshold range with semantic=false, leaving some inference required.

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 names a specific verb (remove duplicates/near-duplicates) and the exact resource (a list of up to 500 strings), then distinguishes itself from generic text utilities by specifying both exact normalization and embedding-based semantic matching. An agent can tell what this does and that it is not text_diff or json_repair.

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?

Use is implied clearly enough (deduplicating a string list), but there is no explicit when-to-use/when-not guidance, no note on what happens above the 500-item cap, and no pointer to an alternative sibling. For a tool with no close sibling, implied usage is acceptable but the boundaries are left for the caller to infer.

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